part one complete

AdventOfCode2025/AdventOfCode2025.csproj

@@ -28,6 +28,10 @@
       <Content Include="Input\DayFour.txt">
         <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
       </Content>
+      <None Remove="Input\DayFive.txt" />
+      <Content Include="Input\DayFive.txt">
+        <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+      </Content>
     </ItemGroup>
 
 </Project>

AdventOfCode2025/Cafeteria.cs

@@ -1,9 +1,35 @@
-namespace AdventOfCode2025;
+using AdventOfCode2025.Utils;
+using Range = AdventOfCode2025.Utils.Range;
+
+namespace AdventOfCode2025;
 
 public class Cafeteria : IAdventSolution
 {
     public AdventSolution Solve(string input)
     {
-        throw new NotImplementedException();
+        var lines = input.SplitLines();
+
+        var ranges = new HashSet<Range>();
+        var startIndex = 0;
+        while (lines[startIndex].Contains("-"))
+        {
+            var line = lines[startIndex++];
+            var parts = line.Split('-');
+            ranges.Add(new(ulong.Parse(parts[0]), ulong.Parse(parts[1])));
+        }
+        
+        var fresh = 0;
+        for(; startIndex < lines.Length; startIndex++)
+        {
+            var line = lines[startIndex++];
+            if (line.Contains('-'))
+                continue;
+
+            var num = ulong.Parse(line);
+            if(ranges.Any(x => x.Min <= num && num <= x.Max)) fresh++;
+        }
+
+        
+        return new AdventSolution(fresh.ToString(), null);
     }
 }