#include <bits/stdc++.h>
using namespace std;
const int maxn = 1005;
const int mod = 998244353;
int main() {
  long long ans = 1;
  long long w, h;
  cin >> w >> h;
  long long sum = w + h;
  while (sum--) {
    ans *= 2;
    ans %= mod;
  }
  cout << ans << endl;
  return 0;
}
