diff --git a/src/day5.rs b/src/day5.rs
new file mode 100644
index 0000000..b108e9f
--- /dev/null
+++ b/src/day5.rs
@@ -0,0 +1,111 @@
+use aoc_runner_derive::{aoc, aoc_generator};
+use itertools::Itertools;
+#[aoc_generator(day5)]
+fn parse(input: &str) -> Vec<(Vec<char>, Vec<char>)> {
+    input.lines()
+    .map(str::chars)
+    .map(itertools::Itertools::collect_vec)
+    .map(|line| {
+        (line[0..7].to_vec(), line[7..].to_vec())
+    }).collect_vec()
+}
+
+fn find_row(row_str: &Vec<char>) -> u64 {
+    let mut range = 0..=127;
+    let mut queue = row_str.iter();
+    while range.try_len().unwrap() != 1 {
+        match queue.next().unwrap() {
+            'F' => {
+                let new_max = range.clone().last().unwrap() - (range.try_len().unwrap() / 2);
+                range = range.clone().next().unwrap()..=new_max;
+            },
+            'B' => {
+                let new_min = range.clone().next().unwrap() + (range.try_len().unwrap() / 2);
+                range = new_min..=range.clone().last().unwrap();
+            },
+            _ => unreachable!()
+        }
+    }
+
+    range.next().unwrap() as u64
+}
+
+fn find_col(col_str: &Vec<char>) -> u64 {
+    let mut range = 0..=7;
+    let mut queue = col_str.iter();
+    while range.try_len().unwrap() != 1 {
+        match queue.next().unwrap() {
+            'L' => {
+                let new_max = range.clone().last().unwrap() - (range.try_len().unwrap() / 2);
+                range = range.clone().next().unwrap()..=new_max;
+            },
+            'R' => {
+                let new_min = range.clone().next().unwrap() + (range.try_len().unwrap() / 2);
+                range = new_min..=range.clone().last().unwrap();
+            },
+            _ => unreachable!()
+        }
+    }
+
+    range.next().unwrap() as u64
+}
+
+#[aoc(day5, part1)]
+fn part1(input: &Vec<(Vec<char>, Vec<char>)>) -> u64 {
+    input.iter().map(|(row_str, col_str)| {
+        let row = find_row(row_str);
+        let col = find_col(col_str);
+        (row * 8) + col
+    }).max().unwrap()
+}
+
+#[aoc(day5, part2)]
+fn part2(input: &Vec<(Vec<char>, Vec<char>)>) -> u64 {
+
+    let filled = input.iter().map(|(row_str, col_str)| {
+        let row = find_row(row_str);
+        let col = find_col(col_str);
+        (row, col)
+    }).collect_vec();
+
+    let mut all: Vec<(u64, u64)> = (0..=127).flat_map(|row| {
+        let mut vec = vec![];
+        for col in 0..=7 {
+            vec.push((row, col))
+        }
+        vec
+    }).collect_vec();
+
+    for full in filled {
+        let idx = all.iter().position(|test| test == &full).unwrap();
+        all.remove(idx);
+    }
+
+    for seats in all.windows(2) {
+        if seats[1].0 - seats[0].0 > 1 && seats[1].1 as i32 - seats[0].1 as i32 > 1 {
+            return (seats[1].0 * 8) + seats[1].1
+        }
+    }
+    unreachable!("mega cringe")
+}
+
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+const EX: &str = r"FBFBBFFRLR
+BFFFBBFRRR
+FFFBBBFRRR
+BBFFBBFRLL";
+
+    #[test]
+    fn part1_example() {
+        assert_eq!(part1(&parse(EX)), 820);
+    }
+
+    // #[test]
+    // fn part2_example() {
+    //     assert_eq!(part2(&parse("<EXAMPLE>")), "<RESULT>");
+    // }
+}
\ No newline at end of file
diff --git a/src/lib.rs b/src/lib.rs
index 0ad7566..f9c2e11 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,3 +1,4 @@
+mod day5;
 mod day1;
 mod day4;
 mod day3;