diff --git a/2020/setup_day.sh b/2020/setup_day.sh
index 414422c..5ec4716 100755
--- a/2020/setup_day.sh
+++ b/2020/setup_day.sh
@@ -8,14 +8,15 @@ sed -i -e '$a\' inputs/day$today
 
 echo '#![feature(test)]
 extern crate test;
-use std::env;
+use aoc::common::*;
 
 type Parsed = Vec<usize>;
 
 fn read_input() -> String {
-    std::fs::read_to_string(env::args().nth(1).filter(|n| n != "--bench").unwrap_or_else(||String::from("inputs/day'$today'"))).unwrap()
+    read_file('$today')
 }
 
+
 fn parse_input(raw: &str) -> Parsed {
     unimplemented!()
 }
diff --git a/2020/src/bin/day01.rs b/2020/src/bin/day01.rs
index 1c3792b..f1c8329 100644
--- a/2020/src/bin/day01.rs
+++ b/2020/src/bin/day01.rs
@@ -1,16 +1,10 @@
 #![feature(test, bool_to_option)]
 extern crate test;
+use aoc2020::common::*;
 use itertools::Itertools;
-use std::env;
 
 fn read_input() -> String {
-    std::fs::read_to_string(
-        env::args()
-            .nth(1)
-            .filter(|n| n != "--bench")
-            .unwrap_or_else(|| String::from("inputs/day01")),
-    )
-    .unwrap()
+    read_file(1)
 }
 
 fn parse_input(input: &str) -> Vec<usize> {
diff --git a/2020/src/bin/day02.rs b/2020/src/bin/day02.rs
index 5f327c8..1f103cf 100644
--- a/2020/src/bin/day02.rs
+++ b/2020/src/bin/day02.rs
@@ -1,7 +1,8 @@
 #![feature(test)]
 extern crate test;
+use aoc2020::common::*;
 use itertools::Itertools;
-use std::{env, ops::RangeInclusive};
+use std::ops::RangeInclusive;
 use text_io::scan;
 
 #[derive(Debug)]
@@ -42,16 +43,7 @@ impl PasswordVerification {
 }
 
 fn read_input() -> Vec<PasswordVerification> {
-    std::fs::read_to_string(
-        env::args()
-            .nth(1)
-            .filter(|n| n != "--bench")
-            .unwrap_or_else(|| String::from("inputs/day02")),
-    )
-    .unwrap()
-    .lines()
-    .map_into()
-    .collect()
+    read_file(2).lines().map_into().collect()
 }
 
 fn main() {
diff --git a/2020/src/bin/day03.rs b/2020/src/bin/day03.rs
index b1b8779..f010ca1 100644
--- a/2020/src/bin/day03.rs
+++ b/2020/src/bin/day03.rs
@@ -1,8 +1,9 @@
 #![feature(iter_map_while)]
 #![feature(test)]
 extern crate test;
+use aoc2020::common::*;
 use itertools::Itertools;
-use std::{env, iter};
+use std::iter;
 
 #[derive(Debug, PartialEq, Copy, Clone)]
 enum Tile {
@@ -29,13 +30,7 @@ impl From<u8> for Tile {
 }
 
 fn read_input() -> String {
-    std::fs::read_to_string(
-        env::args()
-            .nth(1)
-            .filter(|n| n != "--bench")
-            .unwrap_or_else(|| String::from("inputs/day03")),
-    )
-    .unwrap()
+    read_file(3)
 }
 
 fn parse_input(raw: &str) -> Forest {
diff --git a/2020/src/bin/day04.rs b/2020/src/bin/day04.rs
index c898b01..fa0ef74 100644
--- a/2020/src/bin/day04.rs
+++ b/2020/src/bin/day04.rs
@@ -1,9 +1,9 @@
 #![feature(test)]
 extern crate test;
+use aoc2020::common::*;
 use lazy_static::lazy_static;
 use regex::Regex;
 use serde::{Deserialize, Serialize};
-use std::env;
 
 #[derive(Serialize, Deserialize, Debug, Clone)]
 struct Passport {
@@ -18,13 +18,7 @@ struct Passport {
 }
 
 fn read_input() -> String {
-    std::fs::read_to_string(
-        env::args()
-            .nth(1)
-            .filter(|n| n != "--bench")
-            .unwrap_or_else(|| String::from("inputs/day04")),
-    )
-    .unwrap()
+    read_file(4)
 }
 
 /// When I first saw the input and puzzle, I thought
diff --git a/2020/src/bin/day05.rs b/2020/src/bin/day05.rs
index 67a5e31..298937d 100644
--- a/2020/src/bin/day05.rs
+++ b/2020/src/bin/day05.rs
@@ -1,7 +1,8 @@
 #![feature(test, map_first_last, binary_heap_into_iter_sorted)]
 extern crate test;
+use aoc2020::common::*;
 use itertools::Itertools;
-use std::{collections::BinaryHeap, env};
+use std::collections::BinaryHeap;
 
 const NUM_ROWS: usize = 128;
 const NUM_COLS: usize = 8;
@@ -50,13 +51,7 @@ fn main() {
 }
 
 fn read_input() -> String {
-    std::fs::read_to_string(
-        env::args()
-            .nth(1)
-            .filter(|n| n != "--bench")
-            .unwrap_or_else(|| String::from("inputs/day05")),
-    )
-    .unwrap()
+    read_file(5)
 }
 
 #[cfg(test)]
diff --git a/2020/src/bin/day06.rs b/2020/src/bin/day06.rs
index 682da1c..a35b1db 100644
--- a/2020/src/bin/day06.rs
+++ b/2020/src/bin/day06.rs
@@ -1,6 +1,7 @@
 #![feature(test)]
 extern crate test;
-use std::{collections::HashSet, env};
+use aoc2020::common::*;
+use std::collections::HashSet;
 
 fn main() {
     let input = parse_input(&read_input());
@@ -9,13 +10,7 @@ fn main() {
 }
 
 fn read_input() -> String {
-    std::fs::read_to_string(
-        env::args()
-            .nth(1)
-            .filter(|n| n != "--bench")
-            .unwrap_or_else(|| String::from("inputs/day06")),
-    )
-    .unwrap()
+    read_file(6)
 }
 
 fn parse_input(raw: &str) -> Vec<Vec<HashSet<char>>> {
diff --git a/2020/src/bin/day07.rs b/2020/src/bin/day07.rs
index 7ebc5c5..8b95956 100644
--- a/2020/src/bin/day07.rs
+++ b/2020/src/bin/day07.rs
@@ -1,6 +1,7 @@
 #![feature(test)]
-use std::{collections::HashSet, env};
+use std::collections::HashSet;
 extern crate test;
+use aoc2020::common::*;
 
 const COLOR: &str = "shiny gold";
 
@@ -46,13 +47,7 @@ impl From<&str> for Bag {
 }
 
 fn read_input() -> String {
-    std::fs::read_to_string(
-        env::args()
-            .nth(1)
-            .filter(|n| n != "--bench")
-            .unwrap_or_else(|| String::from("inputs/day07")),
-    )
-    .unwrap()
+    read_file(7)
 }
 
 fn part1<'a, 'b>(bags: &'b [Bag], color: &str, seen: &'a mut HashSet<&'b str>) -> &'a mut HashSet<&'b str> {
diff --git a/2020/src/bin/day08.rs b/2020/src/bin/day08.rs
index 8e2205e..a63ff4c 100644
--- a/2020/src/bin/day08.rs
+++ b/2020/src/bin/day08.rs
@@ -1,6 +1,6 @@
 #![feature(test, str_split_once)]
 extern crate test;
-use std::env;
+use aoc2020::common::*;
 
 #[derive(Debug, PartialEq)]
 enum Command {
@@ -10,13 +10,7 @@ enum Command {
 }
 
 fn read_input() -> String {
-    std::fs::read_to_string(
-        env::args()
-            .nth(1)
-            .filter(|n| n != "--bench")
-            .unwrap_or_else(|| String::from("inputs/day08")),
-    )
-    .unwrap()
+    read_file(8)
 }
 
 fn parse_input(raw: &str) -> Vec<Command> {
diff --git a/2020/src/bin/day09.rs b/2020/src/bin/day09.rs
index 699ad32..a91889b 100644
--- a/2020/src/bin/day09.rs
+++ b/2020/src/bin/day09.rs
@@ -1,17 +1,11 @@
 #![feature(test)]
 extern crate test;
-use std::env;
+use aoc2020::common::*;
 
 use itertools::{Itertools, MinMaxResult};
 
 fn read_input() -> String {
-    std::fs::read_to_string(
-        env::args()
-            .nth(1)
-            .filter(|n| n != "--bench")
-            .unwrap_or_else(|| String::from("inputs/day09")),
-    )
-    .unwrap()
+    read_file(9)
 }
 
 fn parse_input(raw: &str) -> Vec<usize> {
diff --git a/2020/src/bin/day10.rs b/2020/src/bin/day10.rs
index 2c53818..3f7b367 100644
--- a/2020/src/bin/day10.rs
+++ b/2020/src/bin/day10.rs
@@ -1,6 +1,6 @@
 #![feature(test)]
 extern crate test;
-use std::env;
+use aoc2020::common::*;
 
 use itertools::Itertools;
 
@@ -9,13 +9,7 @@ type Parsed = Vec<usize>;
 const STEP_SIZE: usize = 3;
 
 fn read_input() -> String {
-    std::fs::read_to_string(
-        env::args()
-            .nth(1)
-            .filter(|n| n != "--bench")
-            .unwrap_or_else(|| String::from("inputs/day10")),
-    )
-    .unwrap()
+    read_file(10)
 }
 
 fn parse_input(raw: &str) -> Parsed {
diff --git a/2020/src/common.rs b/2020/src/common.rs
new file mode 100644
index 0000000..9d64604
--- /dev/null
+++ b/2020/src/common.rs
@@ -0,0 +1,11 @@
+use std::env;
+
+pub fn read_file(day: usize) -> String {
+    std::fs::read_to_string(
+        env::args()
+            .nth(1)
+            .filter(|n| n != "--bench")
+            .unwrap_or_else(|| format!("inputs/day{:0>2}", day)),
+    )
+    .unwrap()
+}
diff --git a/2020/src/lib.rs b/2020/src/lib.rs
index 31de36e..88aa814 100644
--- a/2020/src/lib.rs
+++ b/2020/src/lib.rs
@@ -1 +1,2 @@
 pub mod teststuff;
+pub mod common;