#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 pwab5(unsigned long long a, unsigned long long b) {
  long long r = 1;
  while (b) {
    if (b % 2) r = (r * a) % 998244353;
    a = (a * a) % 998244353;
    b /= 2;
  }
  return (unsigned long long)r;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  unsigned long long w, h;
  cin >> w >> h;
  cout << pwab5(2, w + h);
  return 0;
}
