That Nim Flashbacks

Lettme introduce you to ackermann's function:

int ack(int m, int n) {
    if (m == 0) {
        return n+1;
    } else if((m > 0) && (n == 0)){
        return ack(m-1, 1);
    } else if((m > 0) && (n > 0)) {
        return ack(m-1, ack(m, n-1));
    }
}

You won't run out of stackoverflows any time soon.