Changing the line to use the right function.

src/main.rs

@@ -25,7 +25,7 @@ fn main() {
     }
     {
         let file_path = "prob4_part1.txt";
-        let max_part1 = prob4::solve_part1(file_path);
+        let max_part1 = prob4::solve(file_path, &prob4::mutual_inclusion);
         println!("Solution for problem 4 part 1: {max_part1}");
     }
 }