#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
#define rep(i, n) for (int i = 0; i < (n); ++i)

using namespace std;
using mint = modint998244353;

int main() {
    cin.tie(nullptr) -> sync_with_stdio(false);
    
    int n;
    string a;
    cin >> n >> a;

    vector<int> b;
    for (int i = 0; i < n;) {
        int j = i;
        while (j < n and a[j] == a[i]) ++j;
        b.push_back(j-i);
        i = j;
    }

    mint ans = 1;
    int st = (a[0] == '0' ? 0 : 1);

    for (int i = st; i+1 < b.size(); i += 2) {
        ans *= b[i]+b[i+1]+1;
    }

    cout << ans.val() << '\n';
    
    return 0;
}