#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll = long long;
using ull = unsigned long long;
template <class T> bool chmax(T &a, const T &b) {if (a < b) {a = b; return 1;} return 0;}
template <class T> bool chmin(T &a, const T &b) {if (b < a) {a = b; return 1;} return 0;}
const int INF = INT_MAX / 2;
const ll LINF = 1LL << 60;
const vector<int> dx = {-1, 0, 1, 0}, dy = {0, 1, 0, -1};
using mint = modint998244353;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n;
  cin >> n;
  string s;
  cin >> s;
  int r = 0;
  mint ans = 1;
  for (int l = 0; l < n;) {
    if (s[l] == '0') {
      l++;
      r++;
    } else {
      r++;
      while (r < n && s[r] == '0') {
        r++;
      }
      if (r == n) {
        break;
      } else {
        ans *= (r - l + 1);
        l = r;
      }
    }
  }
  cout << ans.val() << '\n';
  return 0;
}