#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0), cout.tie(0);
  ll w, h;
  cin >> w >> h;
  ll ans = 4;
  for (int i = 1; i < w; i++) {
    ans = (ans * 2LL) % 998244353;
  }
  for (int i = 1; i < h; i++) {
    ans = (ans * 2LL) % 998244353;
  }
  cout << ans << endl;
  return 0;
}
