#include <bits/stdc++.h>

using namespace std;

const int mod = 998244353;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int n;
  string a;
  cin >> n >> a;
  int ans = 1;
  for (int i = 0; i < n; ) {
    int cnt0 = 0, cnt1 = 0;
    while (i < n && a[i] == '0') {
      i += 1;
      cnt0 += 1;
    }
    while (i < n && a[i] == '1') {
      i += 1;
      cnt1 += 1;
    }
    if (cnt0 == 0 || cnt1 == 0) {
      break;
    }
    ans = int64_t(ans) * (cnt0 + cnt1 + 1) % mod;
  }
  cout << ans << '\n';
  return 0;
}