diff --git a/.run/Run-aoc2022-bench-dayX.run.xml b/.run/Run-aoc2022-bench-dayX.run.xml
index 5f016a3..9b49f10 100644
--- a/.run/Run-aoc2022-bench-dayX.run.xml
+++ b/.run/Run-aoc2022-bench-dayX.run.xml
@@ -1,6 +1,6 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="Run-aoc2022-bench-dayX" type="CargoCommandRunConfiguration" factoryName="Cargo Command">
-    <option name="command" value="run --package advent-of-code-2022-rust --bin advent-of-code-2022-rust --release -- -d 3 -b 1000" />
+    <option name="command" value="run --package advent-of-code-2022-rust --bin advent-of-code-2022-rust --release -- -d 4 -b 1000" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
     <option name="channel" value="DEFAULT" />
     <option name="requiredFeatures" value="true" />
diff --git a/input/day4.txt b/input/day4.txt
new file mode 100644
index 0000000..a8c8b2b
--- /dev/null
+++ b/input/day4.txt
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+65-88,10-65
+80-85,25-29
+13-74,12-14
+82-83,83-91
+86-87,61-87
+3-29,26-52
+13-35,12-36
+38-82,38-83
+5-5,4-98
+15-16,16-65
+24-64,29-65
+36-79,29-80
+54-62,53-55
+15-16,15-92
+42-44,43-88
+9-98,9-97
+8-79,45-80
+24-96,20-98
+5-37,4-6
+37-38,38-86
+72-74,24-73
+47-47,37-47
+9-92,8-8
+52-52,52-57
+68-84,80-99
+31-71,32-70
+10-81,9-81
+80-81,28-81
+12-98,13-98
+8-11,9-10
+11-60,12-12
+6-90,6-91
+24-55,23-55
+7-33,92-98
+31-51,32-50
+50-50,13-49
+62-70,20-69
+2-66,66-66
+42-61,10-95
+89-89,6-88
+35-66,34-35
+73-93,10-72
+91-95,59-91
+15-25,23-32
+22-95,22-92
+1-14,4-91
+57-61,57-64
+43-44,43-94
+68-83,69-84
+61-61,3-61
+7-61,8-14
+8-42,8-41
+77-87,77-88
+64-82,18-73
+25-85,26-26
+37-37,36-37
+71-73,16-71
+72-76,49-76
+39-87,40-86
+24-93,25-59
+78-86,79-83
+22-24,23-81
+36-90,89-91
+3-45,5-81
+13-91,14-14
+58-68,43-79
+15-25,24-25
+11-19,12-18
+37-81,32-62
+43-92,93-93
+78-82,46-76
+92-97,96-96
+90-93,43-90
+15-95,3-96
+15-45,15-46
+66-66,66-72
+12-12,10-13
+64-68,63-69
+67-73,66-74
+13-97,2-10
+1-96,1-95
+4-56,56-56
+7-94,8-46
+83-85,4-84
+68-68,12-68
+8-28,9-27
+11-70,10-69
+31-57,31-70
+10-51,8-52
+7-64,7-63
+44-49,43-58
+25-43,41-42
+44-44,43-92
+61-88,39-62
+5-64,5-5
+37-42,43-43
+52-96,57-97
+98-99,92-95
+4-14,3-97
+26-96,27-96
+57-77,63-77
+25-79,78-96
+20-40,21-58
+42-90,42-91
+26-37,26-38
+37-41,42-62
+3-84,2-4
+20-96,45-99
+8-57,20-56
+21-94,20-21
+66-91,65-84
+2-97,1-95
+3-60,2-3
+2-50,3-79
+2-92,2-92
+15-16,15-22
+1-2,3-88
+3-91,79-90
+34-37,37-68
+9-85,89-92
+77-93,29-31
+31-31,11-30
+10-19,10-32
+5-93,6-30
+57-78,76-90
+34-35,34-73
+31-67,11-68
+6-80,6-6
+36-43,42-44
+45-90,46-90
+5-6,5-66
+19-26,18-40
+33-99,32-34
+7-83,82-87
+45-58,57-57
+2-62,1-63
+5-97,99-99
+2-90,91-91
+39-40,40-61
+57-75,25-75
+1-80,1-43
+10-36,35-99
+17-34,35-35
+66-84,34-84
+77-77,31-77
+14-47,14-78
+54-58,22-93
+92-92,5-92
+74-91,75-95
+2-98,97-99
+44-44,43-43
+8-98,97-97
+36-36,25-37
+81-82,79-85
+38-54,88-94
+18-97,7-97
+12-73,12-72
+62-62,2-63
+2-3,3-78
+73-79,47-73
+31-74,31-75
+2-59,3-8
+30-77,5-29
+30-82,30-85
+6-99,6-99
+41-81,81-99
+30-57,25-58
+82-83,23-83
+22-36,21-37
+8-85,9-9
+25-36,25-26
+10-82,81-82
+65-93,65-65
+21-75,22-75
+95-98,47-96
+42-68,41-69
+96-97,43-96
+1-2,2-99
+56-77,42-56
+56-66,58-66
+95-95,1-95
+60-71,61-72
+42-79,7-69
+4-6,5-73
+39-88,27-40
+28-62,27-63
+21-99,3-22
+15-65,60-73
+52-98,51-52
+3-98,97-97
+30-43,29-42
+31-70,30-71
+26-85,84-86
+45-90,3-90
+53-57,52-58
+59-86,85-87
+41-43,42-78
+5-89,7-89
+76-93,94-94
+3-97,1-98
+31-72,6-72
+5-90,4-89
+12-62,17-62
+6-7,7-47
+24-55,9-17
+17-60,59-59
+63-76,62-65
+3-77,4-34
+17-52,17-18
+63-99,88-98
+2-42,16-35
+85-85,17-85
+25-38,10-38
+16-17,17-86
+50-89,42-89
+47-98,97-98
+9-63,10-10
+16-46,15-16
+41-60,94-94
+28-60,3-29
\ No newline at end of file
diff --git a/input/day4_example.txt b/input/day4_example.txt
new file mode 100644
index 0000000..99a66c5
--- /dev/null
+++ b/input/day4_example.txt
@@ -0,0 +1,6 @@
+2-4,6-8
+2-3,4-5
+5-7,7-9
+2-8,3-7
+6-6,4-6
+2-6,4-8
\ No newline at end of file
diff --git a/src/day4.rs b/src/day4.rs
new file mode 100644
index 0000000..0455527
--- /dev/null
+++ b/src/day4.rs
@@ -0,0 +1,81 @@
+use regex::Regex;
+use crate::day_solver::DaySolver;
+
+use super::util;
+
+struct Range {
+    start: u8,
+    end: u8
+}
+
+struct ElfPair {
+    range1: Range,
+    range2: Range
+}
+
+pub struct Day4 {
+    elfs: Vec<ElfPair>
+}
+
+impl Day4 {
+
+    pub fn create() -> Self {
+        // let lines = util::read_file("input/day4_example.txt");
+        let lines = util::read_file("input/day4.txt");
+
+        // let re = Regex::new(r"(\d+)-(\d+),(\d+)-(\d+)").unwrap();
+        // // Put the input into the day struct
+        // return Day4 {
+        //     elfs: lines.iter().map(|s| {
+        //         let caps = re.captures(s.as_ref())
+        //             .unwrap();
+        //         ElfPair {
+        //             range1: Range {
+        //                 start: caps.get(1).unwrap().as_str().parse().unwrap(),
+        //                 end:  caps.get(2).unwrap().as_str().parse().unwrap()
+        //             },
+        //             range2: Range {
+        //                 start: caps.get(3).unwrap().as_str().parse().unwrap(),
+        //                 end:  caps.get(4).unwrap().as_str().parse().unwrap()
+        //             },
+        //         }
+        //     })
+        //         .collect()
+        // }
+        return Day4 {
+            elfs: lines.iter().map(|s| {
+                let mut split = s.split(",");
+                ElfPair {
+                    range1: Day4::parse_range(split.next().unwrap()),
+                    range2: Day4::parse_range(split.next().unwrap())
+                }
+            })
+                .collect()
+        }
+    }
+
+    fn parse_range(str: &str) -> Range {
+        let mut res = str.split('-');
+        Range {
+            start: res.next().unwrap().parse::<u8>().unwrap(),
+            end: res.next().unwrap().parse::<u8>().unwrap()
+        }
+    }
+}
+
+impl DaySolver for Day4 {
+
+    fn solve_part1(&mut self) -> String {
+        return self.elfs.iter()
+            .filter(|e| (e.range1.start >= e.range2.start && e.range1.end <= e.range2.end) || (e.range2.start >= e.range1.start && e.range2.end <= e.range1.end))
+            .count()
+            .to_string()
+    }
+
+    fn solve_part2(&mut self) -> String {
+        return self.elfs.iter()
+            .filter(|e| e.range1.start <= e.range2.end && e.range1.end >= e.range2.start)
+            .count()
+            .to_string()
+    }
+}
diff --git a/src/dayX.rs b/src/dayX.rs
index ec5b955..d5a4c5b 100644
--- a/src/dayX.rs
+++ b/src/dayX.rs
@@ -12,7 +12,7 @@ impl DayX {
         let lines = util::read_file("input/dayX.txt");
 
         // Put the input into the day struct
-        return Day2 {}
+        return DayX {}
     }
 }
 
diff --git a/src/main.rs b/src/main.rs
index 9dc6e83..0687ba4 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -2,6 +2,7 @@ use std::time::Instant;
 use crate::day1::Day1;
 use crate::day2::Day2;
 use crate::day3::Day3;
+use crate::day4::Day4;
 use crate::day_solver::DaySolver;
 
 mod util;
@@ -9,8 +10,9 @@ mod day1;
 mod day_solver;
 mod day2;
 mod day3;
+mod day4;
 
-const MAX_DAY: u8 = 2;
+const MAX_DAY: u8 = 4;
 const DEFAULT_BENCHMARK_AMOUNT: u32 = 100;
 
 fn main() {
@@ -55,11 +57,12 @@ fn main() {
         print_bench_result(&bench_results, |b| b.init, "Initialization");
         print_bench_result(&bench_results, |b| b.part1, "Part 1");
         print_bench_result(&bench_results, |b| b.part2, "Part 2");
+        print_bench_result(&bench_results, |b| b.part1 + b.part2, "Part 1 & 2 together");
 
-        println!("First time took {} μs (init {} μs, part 1: {} μs, part 2: {} μs", first_run_bench.total, first_run_bench.init, first_run_bench.part1, first_run_bench.part2);
+        println!("First time took {} μs (init {} μs, part 1: {} μs, part 2: {} μs)", first_run_bench.total, first_run_bench.init, first_run_bench.part1, first_run_bench.part2);
 
     } else {
-        println!("Execution took {} μs (init {} μs, part 1: {} μs, part 2: {} μs", first_run_bench.total, first_run_bench.init, first_run_bench.part1, first_run_bench.part2);
+        println!("Execution took {} μs (init {} μs, part 1: {} μs, part 2: {} μs)", first_run_bench.total, first_run_bench.init, first_run_bench.part1, first_run_bench.part2);
     }
 }
 
@@ -76,6 +79,7 @@ fn build_day_solver(day: u8) -> Option<Box<dyn DaySolver>> {
         1 => Some(Box::new(Day1::create())),
         2 => Some(Box::new(Day2::create())),
         3 => Some(Box::new(Day3::create())),
+        4 => Some(Box::new(Day4::create())),
         _ => None
     }
 }