#include int ack(int m, int n) { if (m == 0) return n+1; else if (n == 0) return ack(m-1, 1); else return ack(m-1, ack(m, n-1)); } int main(int argc, char **argv) { int m = 3, n = 9; if (argc > 1) m = atoi(argv[1]); if (argc > 2) n = atoi(argv[2]); printf("%d\n", ack(m, n)); return 0; }