/*
 * Program from Ex.6 of
 * 2001POPL - Lee,Jones,Ben-Amram - The size-change principle for program termination
 * where we abstracted lists by their size.
 *
 * Date: 12.12.2013
 * Author: heizmann@informatik.uni-freiburg.de
 *
 */

extern int __VERIFIER_nondet_int(void);

int f(int a, int b);

int g(int c, int d);

int f(int a, int b) {
	if (b == 0) {
		return g(a, 0);
	} else {
		return f(1+a, b-1);
	}
}

int g(int c, int d) {
	if (c == 0) {
		return d;
	} else {
		return g(c-1, 1+d);
	}
}

int main() {
	int a = __VERIFIER_nondet_int();
	int b = __VERIFIER_nondet_int();
	if (a >= 0 && b >= 0) {
		f(a, b);
	}
	return 0;
}