function gcd(a, b) {
-  if (b === 0) return a;
-  return gcd(b, a % b);
+  const bigA = BigInt(a);
+  const bigB = BigInt(b);
+  return bigB === 0n ? bigA : gcd(bigB, bigA % bigB);
 }
 
 function lcm(a, b) {
-  return (a * b) / gcd(a, b);
+  return (BigInt(a) * BigInt(b)) / gcd(a, b);
 }

 function solution(arr) {
-  let answer = arr[0];
-
-  for (let idx = 1; idx < arr.length; idx++) {
-      answer = lcm(answer, arr[idx]);
-  }
-  
-  return answer;
+  return arr.reduce((acc, curr) => lcm(acc, curr));
 }