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

int n;
string a;
int main() {
    cin >> n >> a;
    ll ans = 1,now = 0;
    for(int i = 0; i < n - 1; i++){
        if(a[i] == '1' && a[i + 1] == '0') {
            int l = i - now + 1;
            if(a[now] == '0' && a[i] == '1'){
                ans *= (l + 1);
                ans %= 998244353;
            }
            now = i + 1;
        }
    }
    int l = n - now;
    if(l && a[now] == '0' && a[n - 1] == '1'){
        ans *= (l + 1);
        ans %= 998244353;
    }
    cout << ans << endl;
}