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

static constexpr long long MOD = 998244353;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

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

    long long ans = 1;
    int start = 0;

    auto apply_segment = [&](int l, int r) {
        if (l > r) return;
        bool has0 = false, has1 = false;
        for (int i = l; i <= r; ++i) {
            has0 |= (A[i] == '0');
            has1 |= (A[i] == '1');
        }
        if (has0 && has1) {
            ans = ans * (r - l + 2LL) % MOD;
        }
    };

    for (int i = 0; i + 1 < N; ++i) {
        if (A[i] == '1' && A[i + 1] == '0') {
            apply_segment(start, i);
            start = i + 1;
        }
    }
    apply_segment(start, N - 1);

    cout << ans << '\n';
    return 0;
}