#include <iostream.h>

float ack(float m,float n)
{
  if (n == 0)
    return 0;
  else if (m == 0)
    return 2*n;
  else if (n == 1)
    return 2;
  else
    return ack(m-1,ack(m,n-1));
}

int main()
{
  float x,y;
  
  cin >> x >> y;
  cout << ack(x,y) << endl;

  return 0;
}