#include <bits/stdc++.h>
using namespace std;
long long bigmod(long long a, long long p, long long m) {
  long long res = 1;
  long long x = a;
  while (p) {
    if (p & 1) {
      res = (res * x) % m;
    }
    x = (x * x) % m;
    p = p >> 1;
  }
  return res;
}
int main() {
  ios_base::sync_with_stdio(0);
  long long int w, h;
  cin >> w >> h;
  cout << (bigmod(2, w, 998244353) * bigmod(2, h, 998244353)) % 998244353
       << endl;
  return 0;
}
