#include <bits/stdc++.h>
using namespace std;
constexpr int MOD = 998244353;
int main() {
  int R, C;
  cin >> R >> C;
  int X = 1;
  while (R--) X = (2 * X) % MOD;
  while (C--) X = (2 * X) % MOD;
  cout << X << endl;
}
