findSum = [49, 81, 81, 64];

Function findLargest(arr) {
var largest = Math.max.apply(Math, arr);
return largest;
};
console.log(findLargest(findSum));

var numbers = ['4916-2600-1804-0530', '4779-252888-3972',
'4252-278893-7978', '4556-4242-9283-2260'];