#include <bits/stdc++.h>
int main() {
  std::istream& is = std::cin;
  std::ostream& os = std::cout;
  const int m = 998244353;
  int w, h, i, ans;
  is >> w >> h;
  ans = 1;
  for (i = 0; i < w + h; i++) ans = (ans * 2) % m;
  os << ans;
  return 0;
}
