function mygcd(x,y){
let larger;
let smaller;
if ((x - y) > 0 ) {
larger = x;
smaller = y;
} else {
larger = y;
smaller = x;
}
let diff = larger - smaller;
if (larger%smaller == 0) {
console.log(smaller);
return smaller;
} else {
mygcd(smaller, diff);
}
}