El mayor divisor común C

/* Function using "Euclidian Algorithm" to recursively find the 
greatest common divisor/factor (GCD/GCF) of 2 positive numbers*/
const gcf = function (small, large) {
    let r = large % small;
    if (r == 0)
        return small;
    else
        return gcf(r, small);
}
Saf1