#include <bits/stdc++.h>
const double PI = 2.0 * acos(0.0);
const double EPS = 1e-9;
using namespace std;
int dr[] = {-1, 0, 1, 0, 1, 1, -1, -1};
int dc[] = {0, 1, 0, -1, -1, 1, -1, 1};
unsigned long long power(unsigned long long x, unsigned long long y,
                         unsigned long long p) {
  unsigned long long res = 1;
  x = x % p;
  while (y > 0) {
    if (y & 1) res = (res * x) % p;
    y = y >> 1;
    x = (x * x) % p;
  }
  return res;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  unsigned long long w, h;
  cin >> w >> h;
  cout << power(2, w + h, 998244353);
  return 0;
}
