diff --git a/advent_derive/src/lib.rs b/advent_derive/src/lib.rs
index 29e636f..25a0619 100644
--- a/advent_derive/src/lib.rs
+++ b/advent_derive/src/lib.rs
@@ -40,7 +40,7 @@ pub fn advent_day(attrs: TokenStream, item: TokenStream, ) -> TokenStream {
                 read_input_part1(self, Path::new(#input_str))
             }
 
-            fn solve(&mut self) -> Result<u64, AdventError> {
+            fn solve(&mut self) -> Result<String, AdventError> {
                 solve_part1(self)
             }
         }
@@ -50,7 +50,7 @@ pub fn advent_day(attrs: TokenStream, item: TokenStream, ) -> TokenStream {
                 read_input_part2(self, Path::new(#input_str))
             }
 
-            fn solve(&mut self) -> Result<u64, AdventError> {
+            fn solve(&mut self) -> Result<String, AdventError> {
                 solve_part2(self)
             }
         }
@@ -70,12 +70,12 @@ pub fn advent_day(attrs: TokenStream, item: TokenStream, ) -> TokenStream {
         }          
 
         impl AdventDay for #ident {
-            fn puzzle1(&mut self) -> Result<u64, AdventError> {
+            fn puzzle1(&mut self) -> Result<String, AdventError> {
                 self.part1.read_input()?;
                 self.part1.solve()
             }
 
-            fn puzzle2(&mut self) -> Result<u64, AdventError> {
+            fn puzzle2(&mut self) -> Result<String, AdventError> {
                 self.part2.read_input()?;
                 self.part2.solve()
             }
diff --git a/src/days/day1.rs b/src/days/day1.rs
index 1b7738c..3b1ab56 100644
--- a/src/days/day1.rs
+++ b/src/days/day1.rs
@@ -29,12 +29,12 @@ impl Day1 {
 }
 
 impl AdventDay for Day1 {
-    fn puzzle1(&mut self) -> Result<u64, AdventError> {
+    fn puzzle1(&mut self) -> Result<String, AdventError> {
         self.part1.read_input()?;
         self.part1.solve()
     }
     
-    fn puzzle2(&mut self) -> Result<u64, AdventError> {
+    fn puzzle2(&mut self) -> Result<String, AdventError> {
         self.part2.read_input()?;
         self.part2.solve()
     }
@@ -72,17 +72,18 @@ impl AdventDayPart2 for Day1Part2 {
         Ok(())
     }
     
-    fn solve(&mut self) -> Result<u64, AdventError> {
+    fn solve(&mut self) -> Result<String, AdventError> {
         Ok(self.count1.keys().into_iter().map(
             |k| {
-            let s = *k as u64;
-            if self.count2.contains_key(k) {
-                s * self.count1[k] * self.count2[k]
-            }
-            else {
-                0
-            }
-    }).sum())
+                let s = *k as u64;
+                if self.count2.contains_key(k) {
+                    s * self.count1[k] * self.count2[k]
+                }
+                else {
+                    0
+                }
+            }).sum::<u64>().to_string()
+        )
     }
 }
 
@@ -106,7 +107,7 @@ impl AdventDayPart1 for Day1Part1 {
         Ok(())
     }
     
-    fn solve(&mut self) -> Result<u64, AdventError> {
+    fn solve(&mut self) -> Result<String, AdventError> {
         self.list1.sort();
         self.list2.sort();
 
@@ -114,6 +115,6 @@ impl AdventDayPart1 for Day1Part1 {
         .map(|(l, r)| {
             (l - r).abs() as u64
         })
-        .sum::<u64>())
+        .sum::<u64>().to_string())
     }
 }
\ No newline at end of file
diff --git a/src/days/day14.rs b/src/days/day14.rs
index 863ac6f..551a291 100644
--- a/src/days/day14.rs
+++ b/src/days/day14.rs
@@ -71,7 +71,7 @@ fn read_input_part1(part1: &mut Day14Part1, path: &Path) -> Result<(), AdventErr
     Ok(())
 }
 
-fn solve_part1(part1: &mut Day14Part1) -> Result<u64, AdventError> {
+fn solve_part1(part1: &mut Day14Part1) -> Result<String, AdventError> {
     let mut counts : (u64, u64, u64 ,u64) = (0, 0, 0, 0);
 
     let left_half: u32 = (part1.width / 2) as u32;
@@ -100,7 +100,7 @@ fn solve_part1(part1: &mut Day14Part1) -> Result<u64, AdventError> {
             counts.3 += 1;
         }
     }
-    Ok(counts.0 * counts.1 * counts.2 * counts.3)
+    Ok((counts.0 * counts.1 * counts.2 * counts.3).to_string())
 }
 
 fn read_input_part2(part2: &mut Day14Part2, path: &Path) -> Result<(), AdventError> {
@@ -136,10 +136,10 @@ fn suspected_image(part2: &mut Day14Part2, required_cons: u32) -> bool {
     false
 }
 
-fn solve_part2(part2: &mut Day14Part2) -> Result<u64, AdventError> {
+fn solve_part2(part2: &mut Day14Part2) -> Result<String, AdventError> {
     for i in 0 .. u64::MAX {
         if suspected_image(part2, 10) {
-            return Ok(i);
+            return Ok(i.to_string());
         }
         for robot in part2.robots.iter_mut() {
             robot.apply(part2.width, part2.height);
diff --git a/src/days/day2.rs b/src/days/day2.rs
index a63c3c0..5b584af 100644
--- a/src/days/day2.rs
+++ b/src/days/day2.rs
@@ -64,12 +64,12 @@ impl Day2 {
 }
 
 impl AdventDay for Day2 {
-    fn puzzle1(&mut self) -> Result<u64, AdventError> {
+    fn puzzle1(&mut self) -> Result<String, AdventError> {
         self.part1.read_input()?;
         self.part1.solve()
     }
 
-    fn puzzle2(&mut self) -> Result<u64, AdventError> {
+    fn puzzle2(&mut self) -> Result<String, AdventError> {
         self.part2.read_input()?;
         self.part2.solve()
     }
@@ -88,8 +88,8 @@ impl AdventDayPart1 for Day2Part1 {
         Ok(self.reports = read_into_vec::<Report>(Path::new("resources/input2.txt"))?)
     }
 
-    fn solve(&mut self) -> Result<u64, AdventError> {
-        Ok(self.reports.iter().filter(|x| x.safe1()).count().try_into().unwrap())
+    fn solve(&mut self) -> Result<String, AdventError> {
+        Ok(self.reports.iter().filter(|x| x.safe1()).count().to_string())
     }
 }
 
@@ -106,7 +106,7 @@ impl AdventDayPart2 for Day2Part2 {
         Ok(self.reports = read_into_vec::<Report>(Path::new("resources/input2.txt"))?)
     }
 
-    fn solve(&mut self) -> Result<u64, AdventError> {
-        Ok(self.reports.iter().filter(|x| x.safe2()).count().try_into().unwrap())
+    fn solve(&mut self) -> Result<String, AdventError> {
+        Ok(self.reports.iter().filter(|x| x.safe2()).count().to_string())
     }
 }
diff --git a/src/days/day3.rs b/src/days/day3.rs
index 43b66d5..2ec8b59 100644
--- a/src/days/day3.rs
+++ b/src/days/day3.rs
@@ -30,8 +30,8 @@ impl AdventDayPart1 for Day3Part1 {
         Ok(())
     }
 
-    fn solve(&mut self) -> Result<u64, AdventError> {
-        Ok(self.0.iter().fold(Ok(0), |acc, mul| -> Result<u64,AdventError> {Ok(acc? + TryInto::<u64>::try_into(mul.l * mul.r)?)})?)
+    fn solve(&mut self) -> Result<String, AdventError> {
+        Ok(self.0.iter().fold(Ok(0), |acc, mul| -> Result<u64,AdventError> {Ok(acc? + TryInto::<u64>::try_into(mul.l * mul.r)?)})?.to_string())
     }
 }
 
@@ -68,8 +68,8 @@ impl AdventDayPart2 for Day3Part2 {
         Ok(())
     }
 
-    fn solve(&mut self) -> Result<u64, AdventError> {
-        Ok(self.0.iter().fold(Ok(0), |acc, mul| -> Result<u64,AdventError> {Ok(acc? + TryInto::<u64>::try_into(mul.l * mul.r)?)})?)
+    fn solve(&mut self) -> Result<String, AdventError> {
+        Ok(self.0.iter().fold(Ok(0), |acc, mul| -> Result<u64,AdventError> {Ok(acc? + TryInto::<u64>::try_into(mul.l * mul.r)?)})?.to_string())
     }
 }
 
@@ -88,12 +88,12 @@ impl Day3 {
 }
 
 impl AdventDay for Day3 {
-    fn puzzle1(&mut self) -> Result<u64, crate::error::AdventError> {
+    fn puzzle1(&mut self) -> Result<String, crate::error::AdventError> {
         self.part1.read_input()?;
         self.part1.solve()
     }
 
-    fn puzzle2(&mut self) -> Result<u64, crate::error::AdventError> {
+    fn puzzle2(&mut self) -> Result<String, crate::error::AdventError> {
         self.part2.read_input()?;
         self.part2.solve()
     }
diff --git a/src/days/day4.rs b/src/days/day4.rs
index 1dad281..34b7326 100644
--- a/src/days/day4.rs
+++ b/src/days/day4.rs
@@ -38,7 +38,7 @@ fn read_input_part1(part1: &mut Day4Part1, path: &Path) -> Result<(), AdventErro
     Ok(())
 }
 
-fn solve_part1(part1: &mut Day4Part1) -> Result<u64, AdventError> {
+fn solve_part1(part1: &mut Day4Part1) -> Result<String, AdventError> {
     let lr = part1.text.clone();
     let mut ud = vec![];
     let grid_size = part1.text.len();
@@ -123,7 +123,7 @@ fn solve_part1(part1: &mut Day4Part1) -> Result<u64, AdventError> {
             sum += xmas_r.find_iter(s.as_str()).count() as u64;
             sum += samx_r.find_iter(s.as_str()).count() as u64;
             Ok(sum)    
-        })?
+        })?.to_string()
     )
 
 }
@@ -154,7 +154,7 @@ fn is_xmas(part2: &mut Day4Part2, (x, y): (usize, usize)) -> bool {
 }
 
 
-fn solve_part2(part2: &mut Day4Part2) -> Result<u64, AdventError> {
+fn solve_part2(part2: &mut Day4Part2) -> Result<String, AdventError> {
     let text = part2.text.clone();
     Ok(
         text.iter().enumerate().fold(0, |acc, (y, s)| {
@@ -165,7 +165,7 @@ fn solve_part2(part2: &mut Day4Part2) -> Result<u64, AdventError> {
                     acc
                 }
             })
-        })
+        }).to_string()
     )
 }
 
diff --git a/src/days/day5.rs b/src/days/day5.rs
index 0a6b07d..2902901 100644
--- a/src/days/day5.rs
+++ b/src/days/day5.rs
@@ -75,14 +75,14 @@ fn is_correct(part1: &mut Day5Part1, q: Vec<u32>) -> bool {
     })
 }
 
-fn solve_part1(part1: &mut Day5Part1) -> Result<u64, AdventError> {
+fn solve_part1(part1: &mut Day5Part1) -> Result<String, AdventError> {
     Ok(part1.queues.clone().into_iter().filter(
         |q| {
             is_correct(part1, q.clone())
         }
     ).fold(0u64, | acc, item| {
         acc + item[item.len() / 2] as u64
-    }))
+    }).to_string())
 }
 
 fn read_input_part2(part2: &mut Day5Part2, path: &Path) -> Result<(), AdventError> {
@@ -119,7 +119,7 @@ fn is_correct2(part1: &mut Day5Part2, q: Vec<u32>) -> bool {
 }
 
 
-fn solve_part2(part2: &mut Day5Part2) -> Result<u64, AdventError> {
+fn solve_part2(part2: &mut Day5Part2) -> Result<String, AdventError> {
     let mut faulty = part2.queues.clone().into_iter().filter(
         |q| {
             !is_correct2(part2, q.clone())
@@ -148,7 +148,7 @@ fn solve_part2(part2: &mut Day5Part2) -> Result<u64, AdventError> {
         }
         count += queue[queue.len() / 2] as u64;
     }
-    Ok(count)
+    Ok(count.to_string())
 }
 
 
diff --git a/src/days/day6.rs b/src/days/day6.rs
index 92ca854..6d0e713 100644
--- a/src/days/day6.rs
+++ b/src/days/day6.rs
@@ -116,7 +116,7 @@ fn read_input_part1(part1: &mut Day6Part1, path: &Path) -> Result<(), AdventErro
     Ok(())
 }
 
-fn solve_part1(part1: &mut Day6Part1) -> Result<u64, AdventError> {
+fn solve_part1(part1: &mut Day6Part1) -> Result<String, AdventError> {
     let mut spaces = vec![];
     spaces.push(part1.guard.position);
     loop {
@@ -126,7 +126,7 @@ fn solve_part1(part1: &mut Day6Part1) -> Result<u64, AdventError> {
             break;
         }
     }
-    Ok(spaces.iter().unique().count() as u64)
+    Ok(spaces.iter().unique().count().to_string())
 }
 
 fn step(part1: &mut Day6Part1) -> Option<(i32, i32)> {
@@ -197,7 +197,7 @@ fn step2(part2: &mut Day6Part2) -> Option<(i32, i32)> {
     }
 }
 
-fn solve_part2(part2: &mut Day6Part2) -> Result<u64, AdventError> {
+fn solve_part2(part2: &mut Day6Part2) -> Result<String, AdventError> {
     let start_pos = part2.guard.position;
     let start_dir = part2.guard.direction;
 
@@ -250,7 +250,7 @@ fn solve_part2(part2: &mut Day6Part2) -> Result<u64, AdventError> {
         part2.obstacles.remove(remove_index);
     }
 
-    Ok(loops)
+    Ok(loops.to_string())
     
 }
 
diff --git a/src/days/day7.rs b/src/days/day7.rs
index 5861599..7d3062c 100644
--- a/src/days/day7.rs
+++ b/src/days/day7.rs
@@ -64,10 +64,10 @@ fn possible(equation: &&Equation) -> bool {
     possible_answers.contains(&equation.result)
 }
 
-fn solve_part1(part1: &mut Day7Part1) -> Result<u64, AdventError> {
+fn solve_part1(part1: &mut Day7Part1) -> Result<String, AdventError> {
     Ok(part1.equations.iter().filter(possible).fold(0, |acc, equation| {
         acc + equation.result
-    }))
+    }).to_string())
 }
 
 fn read_input_part2(part2: &mut Day7Part2, path: &Path) -> Result<(), AdventError> {
@@ -101,10 +101,10 @@ fn possible2(equation: &&Equation) -> bool {
     possible_answers.contains(&equation.result)
 }
 
-fn solve_part2(part2: &mut Day7Part2) -> Result<u64, AdventError> {
+fn solve_part2(part2: &mut Day7Part2) -> Result<String, AdventError> {
     Ok(part2.equations.iter().filter(possible2).fold(0, |acc, equation| {
         acc + equation.result
-    }))
+    }).to_string())
 }
 
 #[advent_day(Day7Part1, Day7Part2)]
diff --git a/src/days/mod.rs b/src/days/mod.rs
index 1ed6243..b3fbafc 100644
--- a/src/days/mod.rs
+++ b/src/days/mod.rs
@@ -2,17 +2,17 @@ use crate::error::AdventError;
 
 pub trait AdventDayPart1 {
     fn read_input(&mut self) -> Result<(),AdventError>;
-    fn solve(&mut self) -> Result<u64, AdventError>;
+    fn solve(&mut self) -> Result<String, AdventError>;
 }
 
 pub trait AdventDayPart2 {
     fn read_input(&mut self) -> Result<(),AdventError>;
-    fn solve(&mut self) -> Result<u64, AdventError>;
+    fn solve(&mut self) -> Result<String, AdventError>;
 }
 
 pub trait AdventDay {
-    fn puzzle1(&mut self) -> Result<u64, AdventError>;
-    fn puzzle2(&mut self) -> Result<u64, AdventError>;
+    fn puzzle1(&mut self) -> Result<String, AdventError>;
+    fn puzzle2(&mut self) -> Result<String, AdventError>;
 }
 
 pub mod day1;
diff --git a/src/main.rs b/src/main.rs
index 07e0c38..a18ebcd 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -27,12 +27,12 @@ impl DummyDay {
 }
 
 impl AdventDay for DummyDay {
-    fn puzzle1(&mut self) -> Result<u64, AdventError> {
-        Ok(0)
+    fn puzzle1(&mut self) -> Result<String, AdventError> {
+        Ok("0".to_string())
     }
 
-    fn puzzle2(&mut self) -> Result<u64, AdventError> {
-        Ok(0)
+    fn puzzle2(&mut self) -> Result<String, AdventError> {
+        Ok("0".to_string())
     }
 }
 
@@ -60,7 +60,7 @@ fn main() -> Result<(), AdventError> {
             let one_result = day.puzzle1()?;
             let two_result = day.puzzle2()?;
             Ok((one_result, two_result))
-        }).enumerate().map(|(index, r): (usize, Result<(u64, u64), AdventError>)| {
+        }).enumerate().map(|(index, r): (usize, Result<(String, String), AdventError>)| {
             match r {
                 Ok((res1, res2)) => println!("{}: ({}, {})", index + 1, res1, res2),
                 Err(e) => println!("Error: {}", e.0)