#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int main() {
	int a;
	cin >> a;
	string S;
	cin >> S;
	ll nowz = 0ll, nows = 0ll, ans = 1ll;
	bool now = true;//0ならtrueだし1ならfalse
	for (int i = 0; i < a; i++) {
		if (S[i] == '0') {
			if (!now&&nowz) {
				ans *= (nows%998244353ll + 1ll)%998244353ll;
				ans %= 998244353ll;
				nowz = 0ll;
				nows = 0ll;
			}
			now = true;
			nowz++;
			nows++;
		}
		else {
			now = false;
			if (nowz) {
			  nows++;
			}
		}
	}
	if (!now&&nowz) {
		ans *= (nows%998244353ll + 1ll)%998244353ll;
	}
	cout << ans%998244353ll << endl;
}