diff --git a/src/main.rs b/src/main.rs
index c74fc3f..97a0e1a 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,4 +1,4 @@
-use advent_of_code::{prob1, prob2, prob3};
+use advent_of_code::{prob1, prob2, prob3, prob4};
 
 fn main() {
     {
@@ -23,4 +23,9 @@ fn main() {
         let max_part2 = prob3::solve_part2(file_path);
         println!("Solution for problem 3 part 2: {max_part2}");
     }
+    {
+        let file_path = "prob4_part1.txt";
+        let max_part1 = prob4::solve_part1(file_path);
+        println!("Solution for problem 4 part 1: {max_part1}");
+    }
 }
diff --git a/src/prob4/mod.rs b/src/prob4/mod.rs
index e69de29..02c29dc 100644
--- a/src/prob4/mod.rs
+++ b/src/prob4/mod.rs
@@ -0,0 +1,40 @@
+fn mutual_inclusion(first_pair: &[u32], second_pair: &[u32]) -> bool {
+    (first_pair[0] <= second_pair[0] && first_pair[1] >= second_pair[1])
+        || (second_pair[0] <= first_pair[0] && second_pair[1] >= first_pair[1])
+}
+
+pub fn solve_part1(file_path: &str) -> i32 {
+    let result = std::fs::read_to_string(file_path)
+        .expect("Please provide a text file as an argument.")
+        .lines()
+        .map(|line| {
+            let tmp = line.split(',').collect::<Vec<&str>>();
+            let firs_pair = tmp
+                .first()
+                .expect("First character error")
+                .split('-')
+                .map(|first_split| {
+                    first_split
+                        .parse::<u32>()
+                        .expect("Parsing number in first pair failed")
+                })
+                .collect::<Vec<u32>>();
+            let second_pair = tmp
+                .last()
+                .expect("First character error")
+                .split('-')
+                .map(|first_split| {
+                    first_split
+                        .parse::<u32>()
+                        .expect("Parsing number in first pair failed")
+                })
+                .collect::<Vec<u32>>();
+            if mutual_inclusion(&firs_pair, &second_pair) {
+                1
+            } else {
+                0
+            }
+        })
+        .collect::<Vec<i32>>();
+    result.iter().sum()
+}