#include <bits/stdc++.h>
using namespace std;
bool b2(const pair<pair<int, int>, int> &p1,
        const pair<pair<int, int>, int> &p2) {
  return p1.first.first > p2.first.first;
}
bool b1(const pair<pair<int, int>, int> &p1,
        const pair<pair<int, int>, int> &p2) {
  return p1.first.second < p2.first.second;
}
int gcd(long long int a, long long int b) {
  if (b == 0) return a;
  return gcd(b, a % b);
}
long long int binomialCoeff(long long int n, long long int k) {
  long long int C[n + 1][k + 1];
  long long int i, j;
  for (i = 0; i <= n; i++) {
    for (j = 0; j <= min(i, k); j++) {
      if (j == 0 || j == i)
        C[i][j] = 1;
      else
        C[i][j] = ((C[i - 1][j - 1]) % 998244353 + (C[i - 1][j]) % 998244353) %
                  998244353;
    }
  }
  return C[n][k];
}
long long int digsum(long long int a) {
  long long int sum = 0;
  while (a > 0) {
    sum += a % 10;
    a = a / 10;
  }
  return sum;
}
bool bbk(vector<pair<int, int>> &v1, vector<pair<int, int>> &v2) {
  return v1.size() < v2.size();
}
bool bkbk(pair<int, int> &p1, pair<int, int> &p2) {
  return p1.second < p2.second;
}
long long int power(long long int x, long long int y, long long int p) {
  long long int 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() {
  long long int w, h;
  cin >> w >> h;
  cout << power(2, w + h, 998244353) << endl;
  return 0;
}
