Ackermann函数

#include<iostream>
#include<string>
#include<cstring>
using namespace std;
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));
}
int main()
{
    int m, n;
    while (cin >> m >> n && (m != 0 || n != 0))
    {
        cout << Ack(m, n) << endl;
    }
    return 0;
}