[TASK] Implemented Day 6

functions/src/utils.ts

@@ -14,7 +14,11 @@ class Utils {
   }
 
   static sum(values: number[]): number {
-    return values.reduce((a, b) => a + b, 0);
+    return values.reduce((a, b) => a + b);
+  }
+
+  static bigSum(values: bigint[]): bigint {
+    return values.reduce((a, b) => a + b);
   }
 
   static zeroes(length: number): number[] {