#include <bits/stdc++.h>
#include <atcoder/all>
using mint = atcoder::modint998244353;
using namespace std;
vector<pair<int, int>> RLE(string A){
	int N = A.size();
	vector<pair<int, int>> ret;
	for (int l = 0; l < N;){
		int r = l + 1;
		while (r < N and A[l] == A[r]){
			r++;
		};
		ret.push_back({A[l], r - l});
		l = r;
	}
	return ret;
}
int main(){
	int N;
	cin >> N;
	string S;
	cin >> S;
	auto P = RLE(S);
	mint ans = 1;
	int M = P.size();
	for (int i = 1; i < M - 1; i++){
		if (P[i].first == '0'){
			ans *= P[i].second + 2;
		} else {
			ans *= mint(2).pow(P[i].second - 1);
		}
	}
	cout << ans.val() << endl;
}