diff --git a/src/main.rs b/src/main.rs
index f1df36d..4b80c41 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,22 +1,59 @@
+mod day1;
+mod day2;
+mod day3;
+mod day4;
 mod day5;
 
+use std::{env, process};
 use std::fs::File;
 use std::io::prelude::*;
 
-fn main() {
-    let input_filename = "input5.txt";
-
+fn run(day: i32, part: i32, input_filename: &str) {
     let mut input_file = File::open(input_filename)
-        .expect("Input file not found");
+        .expect(format!("Input file '{}' not found", input_filename).as_str());
 
     let mut contents = String::new();
     input_file.read_to_string(&mut contents)
-        .expect("Could not read input file");
+        .expect("Failed to read input file");
 
-    let input = day5::parse_input(&contents)
-        .expect("Failed to parse input");
-    
-    println!("Part 1 result: {}", day5::part1(&input));
-    println!("Part 2 result: {}", day5::part2(&input));
+    // Janky solution so that I could specify what I want to run
+    let parse_error_msg = "Failed to parse input";
+    match format!("{}.{}", day, part).as_str() {
+        "1.1" => println!("{}", day1::part1(&day1::parse_input(&contents).expect(parse_error_msg))),
+        "1.2" => println!("{}", day1::part2(&day1::parse_input(&contents).expect(parse_error_msg))),
+        "2.1" => println!("{}", day2::part1(&day2::parse_input(&contents).expect(parse_error_msg))),
+        "2.2" => println!("{}", day2::part2(&day2::parse_input(&contents).expect(parse_error_msg))),
+        "3.1" => println!("{}", day3::part1(&day3::parse_input(&contents).expect(parse_error_msg))),
+        "3.2" => println!("{}", day3::part2(&day3::parse_input(&contents).expect(parse_error_msg))),
+        "4.1" => println!("{}", day4::part1(&day4::parse_input(&contents).expect(parse_error_msg))),
+        "4.2" => println!("{}", day4::part2(&day4::parse_input(&contents).expect(parse_error_msg))),
+        "5.1" => println!("{}", day5::part1(&day5::parse_input(&contents).expect(parse_error_msg))),
+        "5.2" => println!("{}", day5::part2(&day5::parse_input(&contents).expect(parse_error_msg))),
+        "6.1" => println!("{}", day6::part1(&day6::parse_input(&contents).expect(parse_error_msg))),
+        "6.2" => println!("{}", day6::part2(&day6::parse_input(&contents).expect(parse_error_msg))),
+        _ => println!("Day {} part {} not found", day, part)
+    }
+}
+
+fn main() {
+    let args: Vec<String> = env::args().collect();
+    if args.len() < 3 {
+        println!("Usage: {} <day> <part> [input-file]", args[0]);
+        process::exit(0);
+    }
+
+    let day = args[1].parse::<i32>()
+        .expect("Failed to parse day");
+
+    let part = args[2].parse::<i32>()
+        .expect("Failed to parse part");
+
+    let input_filename;
+    if args.len() > 3 {
+        input_filename = args[3].clone();
+    } else {
+        input_filename = format!("input{}.txt", day);
+    }
+    run(day, part, &input_filename);
 }