#include <bits/stdc++.h>
using namespace std;
bool* Seive(long long n, bool* p) {
  memset(p, 1, sizeof(p));
  long long i, j;
  for (i = 2; i <= n; i++) {
    if (p[i] == 1)
      for (j = i * i; j <= n; j += i) {
        p[j] = 0;
      }
  }
  p[1] = 0;
  return p;
}
long long gcd(long long a, long long b) {
  if (b == 0)
    return a;
  else
    return gcd(b, a % b);
}
long long modexp(long long x, long long y) {
  if (y == 0)
    return 1;
  else if (y % 2 == 0) {
    return modexp((x * x) % (long long)998244353, y / 2);
  } else {
    return (x * modexp((x * x) % (long long)998244353, (y - 1) / 2)) %
           (long long)998244353;
  }
}
long long fact(long long n) {
  long long f = 1;
  for (long long i = 2; i <= n; i++) {
    f = (i % (long long)998244353 * f % (long long)998244353) %
        (long long)998244353;
  }
  return f;
}
long long nCr(long long n, long long r) {
  return (fact(n) * modexp((fact(n - r) * fact(r)) % (long long)998244353,
                           (long long)998244353 - 2)) %
         (long long)998244353;
}
void showlist(list<int> g) {
  list<int>::iterator it;
  for (it = g.begin(); it != g.end(); ++it) cout << *it << " ";
  cout << '\n';
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  long long w, h;
  cin >> w >> h;
  cout << modexp(2, w + h) << endl;
  return 0;
}
