diff --git a/src/01.cs b/src/01.cs
index 8a01230..c5f9a9f 100644
--- a/src/01.cs
+++ b/src/01.cs
@@ -4,7 +4,7 @@ internal class Day01 : Day
 {
     internal override void Go()
     {
-        var lines = File.ReadAllLines("inputs/01.txt");
+        var lines = Util.ReadAllLines("inputs/01.txt");
         Part1(lines);
         Part2(lines);
     }
diff --git a/src/02.cs b/src/02.cs
index a8bf46d..e7e00aa 100644
--- a/src/02.cs
+++ b/src/02.cs
@@ -4,7 +4,7 @@ internal class Day02 : Day
 {
     internal override void Go()
     {
-        var lines = File.ReadAllLines("inputs/02.txt");
+        var lines = Util.ReadAllLines("inputs/02.txt");
         var instructions = new List<Instruction>();
         foreach (var instruction in lines)
         {
diff --git a/src/03.cs b/src/03.cs
index 31c78a1..7369935 100644
--- a/src/03.cs
+++ b/src/03.cs
@@ -4,7 +4,7 @@ internal class Day03 : Day
 {
     internal override void Go()
     {
-        var lines = File.ReadAllLines("inputs/03.txt");
+        var lines = Util.ReadAllLines("inputs/03.txt");
         Part1(lines);
         Part2(lines);
     }
diff --git a/src/05.cs b/src/05.cs
index 183631a..024fb9b 100644
--- a/src/05.cs
+++ b/src/05.cs
@@ -43,7 +43,7 @@ internal class Day05 : Day
 
     internal override void Go()
     {
-        var lines = File.ReadAllLines("inputs/05.txt");
+        var lines = Util.ReadAllLines("inputs/05.txt");
         List<Line> segments = new();
         foreach (var line in lines)
         {
diff --git a/src/08.cs b/src/08.cs
index e56f588..a51fced 100644
--- a/src/08.cs
+++ b/src/08.cs
@@ -4,7 +4,7 @@ internal class Day08 : Day
 {
     internal override void Go()
     {
-        var lines = File.ReadAllLines("inputs/08.txt");
+        var lines = Util.ReadAllLines("inputs/08.txt");
         List<(List<string>, List<string>)> puzzle = new();
         foreach (var line in lines)
         {
diff --git a/src/09.cs b/src/09.cs
index bd12a9f..a99e3f5 100644
--- a/src/09.cs
+++ b/src/09.cs
@@ -4,7 +4,7 @@ internal class Day09 : Day
 {
     internal override void Go()
     {
-        var lines = File.ReadAllLines("inputs/09.txt");
+        var lines = Util.ReadAllLines("inputs/09.txt").ToArray();
         byte[,] grid = new byte[lines.Length, lines[0].Length];
         for (int i = 0; i < lines.Length; i++)
         {
diff --git a/src/10.cs b/src/10.cs
index 9631252..c7ddc99 100644
--- a/src/10.cs
+++ b/src/10.cs
@@ -4,7 +4,7 @@ internal class Day10 : Day
 {
     internal override void Go()
     {
-        var lines = File.ReadAllLines("inputs/10.txt");
+        var lines = Util.ReadAllLines("inputs/10.txt");
         Part1(lines);
         Part2(lines);
     }
diff --git a/src/11.cs b/src/11.cs
index 35da95a..0c34d08 100644
--- a/src/11.cs
+++ b/src/11.cs
@@ -4,7 +4,7 @@ internal class Day11 : Day
 {
     internal override void Go()
     {
-        var lines = File.ReadAllLines("inputs/11.txt");
+        var lines = Util.ReadAllLines("inputs/11.txt").ToArray();
         var grid = new byte[lines.Length, lines[0].Length];
         for (int i = 0; i < lines.Length; i++)
         {
diff --git a/src/12.cs b/src/12.cs
index cce4ae1..8fc6fa9 100644
--- a/src/12.cs
+++ b/src/12.cs
@@ -4,7 +4,7 @@ internal class Day12 : Day
 {
     internal override void Go()
     {
-        var lines = File.ReadAllLines("inputs/12.txt");
+        var lines = Util.ReadAllLines("inputs/12.txt");
         var paths = new Dictionary<string, List<string>>();
         foreach (var line in lines)
         {
diff --git a/src/13.cs b/src/13.cs
index 842ce43..df8adf1 100644
--- a/src/13.cs
+++ b/src/13.cs
@@ -4,7 +4,7 @@ internal class Day13 : Day
 {
     internal override void Go()
     {
-        var lines = File.ReadAllLines("inputs/13.txt");
+        var lines = Util.ReadAllLines("inputs/13.txt");
         int phase = 0;
         var points = new HashSet<(int, int)>();
         var folds = new List<(char, int)>();
diff --git a/src/Template.cs b/src/Template.cs
index 1a56b23..0c4eeb4 100644
--- a/src/Template.cs
+++ b/src/Template.cs
@@ -6,7 +6,7 @@ internal class DayTemplate : Day
     {
         Logger.Log("Day #");
         Logger.Log("-----");
-        var lines = File.ReadAllLines("inputs/##.txt");
+        var lines = Util.ReadAllLines("inputs/##.txt");
         Part1(lines);
         Part2(lines);
         Logger.Log("");
diff --git a/src/Util.cs b/src/Util.cs
new file mode 100644
index 0000000..dfff7ff
--- /dev/null
+++ b/src/Util.cs
@@ -0,0 +1,32 @@
+using System.Text;
+
+namespace aoc2021;
+
+internal static class Util
+{
+    internal static IEnumerable<string> ReadAllLines(string filename)
+    {
+        if (Console.IsInputRedirected)
+        {
+            string? line;
+            List<string> lines = new();
+            while ((line = Console.In.ReadLine()) != null)
+            {
+                if (!lines.Any())
+                {
+                    if (line.StartsWith(Encoding.UTF8.GetString(Encoding.UTF8.GetPreamble())))
+                    {
+                        line = line[Encoding.UTF8.GetPreamble().Length..];
+                    }
+                }
+                lines.Add(line);
+            }
+
+            return lines;
+        }
+        else
+        {
+            return File.ReadAllLines(filename);
+        }
+    }
+}