#include <bits/stdc++.h>
using namespace std;

int main() {
    cin.tie(0)->sync_with_stdio(0);
    cin.exceptions(cin.failbit);
    int H, W;
    cin >> H >> W;
    assert(1 <= min(H, W) && max(H, W) <= 3'000);
    
    assert(H == 1);
    int N = H * W - 1;
    long long ans = 1, mod = 998244353;
    while (N--) {
        ans += ans;
        if (ans >= mod) ans -= mod;
    }
    cout << ans << endl;
    return 0;
}