function divide(l,w){
if(l%w === 0){
return w
}
return divide(w,l%w)
}
function divide(l, w) {
if (l % w === 0) {
return w
}
let pre = l
let prePre = w
if (pre < prePre) {
let a = prePre
prePre = pre
pre = a
}
while (pre % prePre) {
let temp = pre
prePre = pre % prePre
pre = temp
}
return prePre
}
console.log(divide(1680, 640))
console.log(divide(640, 1680))
console.log(divide(80, 40))
console.log(divide(18, 3))