public class Test {

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

  }

  public static void main(String[] d) {
    for (int m = 0; m < 5; m++) {
      for (int n = 0; n < 3; n++) {
        System.out.println("m=" + m + " n=" + n + " ack(m,n)=" + ack(m, n));
      }
    }

  }
}

/*Output:
m=0 n=0 ack(m,n)=1
m=0 n=1 ack(m,n)=2
m=0 n=2 ack(m,n)=3
m=1 n=0 ack(m,n)=2
m=1 n=1 ack(m,n)=3
m=1 n=2 ack(m,n)=4
m=2 n=0 ack(m,n)=3
m=2 n=1 ack(m,n)=5
m=2 n=2 ack(m,n)=7
m=3 n=0 ack(m,n)=5
m=3 n=1 ack(m,n)=13
m=3 n=2 ack(m,n)=29
m=4 n=0 ack(m,n)=13
Exception in thread "main" java.lang.StackOverflowError */