import java.util.*;

public class AkermanEvaluater {
	
	public int evaluate(int m,int n) {
		StackOfIntegers intStack = new StackOfIntegers();
		int initM = m, initN = n;
		intStack.push(m);
		intStack.push;
        while(true) {
        	try{
				n = intStack.pop();
				m = intStack.pop();
				if(m != 0) {
					if(n != 0) {
						intStack.push(m - 1);
						intStack.push(m);
						intStack.push(n - 1);
					}
					else {
						intStack.push(m - 1);
						intStack.push(1);
					}	
				}
				else intStack.push(n + 1);
			}//try
			 catch(EmptyStackException e) { return n; }
			 catch(FullStackException e) {
				throw new ArithmeticException("Impossible computing the value!");
			 }
		}//while
	}//method
}//class

class TestAkermanEvaluater {
	public static void main(String[]args) {
		Scanner s = new Scanner(System.in);
		System.out.println("To stop testing enter: m = 0, n = 0");
		System.out.println("Starting...");
		while(true) {
			try{
                System.out.print("     m = ");
                int m = s.nextInt();
                System.out.print("     n = ");
                int n = s.nextInt();
                if(m == 0 && n == 0) {
                	System.out.println("End of test!");
					break;
                }
                AkermanEvaluater w = new AkermanEvaluater();
                System.out.println("A(" + m + "," + n + ") = " + w.evaluate(m,n));
			}catch(ArithmeticException e) {
				System.out.println(e.getMessage()); }
		}
	}
}
/*
m = 0 n = 1
m = 1 n = 1
m = 2 n = 1
m = 3 n = 0
m = 3 n = 1
m = 3 n = 2
m = 3 n = 3
*/