**Tell us what’s happening:**

Hello,

I’m trying to solve Smallest Common Multiple Algorithm, and it works fine with lower numbers

smallestCommons([1, 5]) should return a number.

Passed

smallestCommons([1, 5]) should return 60.

Passed

smallestCommons([5, 1]) should return 60.

Passed

smallestCommons([2, 10]) should return 2520.

But I get undefined when I try to test:

smallestCommons([1, 13])

smallestCommons([23, 18])

Any ideas?

**Your code so far**

```
function smallestCommons(arr) {
let allNums = [];
let firstInArr = arr[0];
let lastInArr = arr[arr.length - 1];
let counter = 0;
let smallestCommon = 0;
// Create sorted array with all numbers
if(firstInArr <= lastInArr) {
for(let i = firstInArr; i < lastInArr + 1; i++) {
allNums.push(i);
}
}
else if(firstInArr >= lastInArr) {
for(let y = lastInArr; y < firstInArr + 1; y++) {
allNums.push(y);
}
}
// Find smallest common multiple evently divisible
for(let x = allNums[allNums.length - 1]; x < 10000000; x++) {
counter = 0;
allNums.forEach(function(element) {
if(x % element === 0) {
smallestCommon = x;
counter++;
}
});
if(counter === allNums.length) {
return smallestCommon;
}
}
}
console.log(smallestCommons([1, 13]));
smallestCommons([1, 13]);
```

**Your browser information:**

User Agent is: `Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36`

.

**Link to the challenge:**

https://learn.freecodecamp.org/javascript-algorithms-and-data-structures/intermediate-algorithm-scripting/smallest-common-multiple/