编辑代码

#include <stdio.h>

    int GCD(int l, int w)
    {
        if(l%w==0) return w;
        else return GCD(w,l%w);
    }

int main () {
    printf("%d\n",GCD(640,1680));
    printf("%d\n",GCD(1680,640));
    return 0;
}