extern int __VERIFIER_nondet_int(void);

int foo(int y1,int y2){
if (y1 >= 0 && y2 >= 0) {
    	while (y1 != y2) {
	    	if (y1 > y2) {
		    	y1 = y1 - y2;
    		} else {
	    		y2 = y2 - y1;
		    }
	    }
	}
return 0;
}