#include <bits/stdc++.h>
using namespace std;
const int MOD = 998244353;
void solve() {
  int n, m;
  cin >> n >> m;
  long long x = 1, y = 1;
  while (n--) {
    x = (x * 2) % MOD;
  }
  while (m--) {
    y = (y * 2) % MOD;
  }
  cout << (x * y) % MOD;
}
int main() {
  ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
  ;
  int t = 1;
  while (t--) {
    solve();
    cout << "\n";
  }
  return 0;
}
