#include <bits/stdc++.h>
using namespace std;
long long w, a, b, c, c1, c2, c3, d, d1, d2, d3, f, h, k, l, m, n, m1, m2, n1,
    n2, o, p, p1, p2, p3, p4, q, q1, q2, q3, q4, r, s, t, u, v, x, y, z, sum,
    mx = -1e15, mn = 1e15, flg, id1, id2, id3, id4;
void solve() {
  c = 4;
  for (long long i = 1; i < w; i++) {
    c = (c * 2) % 998244353;
  }
  for (long long i = 1; i < h; i++) {
    c = (c * 2) % 998244353;
  }
  printf("%I64d\n", c);
}
int main() {
  scanf("%I64d%I64d", &w, &h);
  solve();
  return 0;
}
