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


int main() {
        long long MOD = 998244353;

        int N;
        string A;
        cin >> N >> A;

        long long ans = 1;

        int l = 0;
        bool has0 = false, has1 = false;

        for (int i = 0; i < N; i++) {
                if (A[i] == '0') has0 = true;
                else has1 = true;
                if (i + 1 == N || (A[i] == '1' && A[i + 1] == '0')) {
                        int len = i - l + 1;
                        if (has0 && has1) {
                                ans = ans * (len + 1) % MOD;
                        }
                        l = i + 1;
                        has0 = has1 = false;
                }
        }

        cout << ans % MOD << endl;
        return 0;
}