#include <cstdlib>
#include <cstdint>
#include <iostream>
#include <map>
using namespace std;
template <typename ack_t>
struct ack_arg {
ack_t m, n;
ack_arg(ack_t m_, ack_t n_) : m(m_), n(n_)
{}
bool operator<(ack_arg<ack_t>& aa){
if (aa == *this)
return false;
return (m < aa.m || n < aa.n);
}
bool operator>(ack_arg<ack_t>& aa){
if (aa == *this)
return false;
return (m > aa.m || n > aa.n);
}
bool operator<=(ack_arg<ack_t>& aa){
return !(*this > aa);
}
bool operator>=(ack_arg<ack_t>& aa){
return !(*this < aa);
}
bool operator==(ack_arg<ack_t>& aa){
if (aa == *this)
return true;
return (m == aa.m || n == aa.n);
}
};

ostream& operator<<(ostream& o, ack_arg<uintmax_t>* a){
o << a->m <<"," << a->n;
return o;
}
map<ack_arg<uintmax_t>*, uintmax_t> memo;
uintmax_t ack(ack_arg<uintmax_t>* a) {
//      cout << a << endl;
        if (memo.find(a) != memo.end())
                return memo[a];
        if (a->m==0) {
                memo[a] = a->n + 1;
                return memo[a];
        }
        else if (a->m > 0 && a->n == 0) {
                memo[a] = ack(new ack_arg<uintmax_t>(a->m-1,1));
                return memo[a];
        } else if (a->m > 0 && a->n > 0) {

                memo[a] = ack(new ack_arg<uintmax_t>(a->m-1,ack(new ack_arg<uintmax_t>(a->m,a->n-1))));
                return memo[a];
        }
}
int main(int argc, char **argv) {
        memo = map<ack_arg<uintmax_t>*, uintmax_t>();
        std::cout << ack(new ack_arg<uintmax_t>(strtoull(argv[1], (char**)NULL, 10), strtoull(argv[2], (char**)NULL, 10))) << std::endl;
        return 0;
}