#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
  #include "settings/debug.cpp"
  #define _GLIBCXX_DEBUG
#else
  #define Debug(...) void(0)
#endif
#define rep(i, n) for (int i = 0; i < (n); ++i)
using ll = long long;
using ull = unsigned long long;

#include <atcoder/modint>
using mint = atcoder::modint998244353;

void operator<<(ostream& os, const mint& m) {
  os << m.val();
}

int main() {
  int n;
  string s;
  cin >> n >> s;
  vector dp(n + 1, vector<mint>(2, 0));
  dp[0][0] = 1;
  rep(i, n) {
    // 分割しない
    dp[i + 1][1] = dp[i][1];
    // 分割する
    dp[i + 1][s[i] == '1'] += dp[i][0] + dp[i][1];
    Debug(dp[i + 1]);
  }
  cout << dp[n][1].val() << endl;
  return 0;
}