#include <iostream>
#include <vector>
using namespace std;
using ll = long long;

int main() {
    int N;
    cin >> N;
    vector<int> c(N);
    for (ll i = 0; i < N; i++) {
        cin >> c[i];
    }
    ll ans = 1;
    for (int i = 0; i < N - 1; i++) {
        ans = (ans * 2LL) % 998244353;
    }
    cout << ans << endl;
}