#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const ll MOD = 998244353;

int main() {
    ll N;
    string A;
    cin >> N >> A;

    A = "1" + A + "0";

    vector<ll> X;
    ll a = 0;
    for (ll i = 0; i < (ll)A.size(); i++) {
        a++;
        if (i == (ll)A.size() - 1 || A[i] != A[i + 1]) {
            X.emplace_back(a);
            a = 0;
        }
    }

    ll ans = 1;
    for (ll i = 1; i + 1 < (ll)X.size(); i += 2) {
        ans *= X[i] + X[i + 1] + 1;
        ans %= MOD;
    }
    cout << ans << endl;
}