#include <bits/stdc++.h>
using namespace std;
const long long mod = 998244353;
long long qucikmod(long long a, long long b, long long mod) {
  long long res = 1;
  while (b > 0) {
    if (b & 1) res = res * a % mod;
    b = b >> 1;
    a = a * a % mod;
  }
  return res;
}
int main() {
  long long w, h;
  cin >> w >> h;
  cout << (qucikmod(2ll, w, mod) * qucikmod(2ll, h, mod)) % mod << endl;
  return 0;
}
