#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
// using mint = modint1000000007;
// const int mod = 1000000007;
using mint = modint998244353;
const int mod = 998244353;
// const int INF = 1e9;
// const long long LINF = 1e18;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i, l, r) for (int i = (l); i < (r); ++i)
#define rrep(i, n) for (int i = (n)-1; i >= 0; --i)
#define rrep2(i, l, r) for (int i = (r)-1; i >= (l); --i)
#define all(x) (x).begin(), (x).end()
#define allR(x) (x).rbegin(), (x).rend()
#define P pair<int, int>
template<typename A, typename B> inline bool chmax(A &a, const B &b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A &a, const B &b) { if (a > b) { a = b; return true; } return false; }

int main() {
	std::ios::sync_with_stdio(false);
	std::cin.tie(nullptr);
	int n; cin >> n;
	string s; cin >> s;
	while (!s.empty() && s.back() == '0')s.pop_back();
	reverse(all(s));
	while (!s.empty() && s.back() == '1')s.pop_back();
	reverse(all(s));
	mint ans = 1;
	n = s.size();
	for (int i = 0; i < n;) {
		int j = i + 1;
		while (j < n && s[j - 1] <= s[j])j++;
		ans *= j - i + 1;
		i = j;
	}
	cout << ans.val() << endl;
	return 0;
}