#include <stdio.h>
#include <atcoder/all>
#include <bits/stdc++.h>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf32 1000000001
#define Inf64 4000000000000000001LL

int main(){
	
	int n;
	cin>>n;
	string s;
	cin>>s;
	vector<mint> dp;
	int pos = -1;
	rep(i,n){
		if(s[i]=='0'){
			pos = i;break;
		}
	}
	if(pos==-1){
		mint ans = 1;
		rep(i,n)ans *= i+1;
		cout<<ans.val()<<endl;
		return 0;
	}
	{
		mint t = 1;
		rep(i,pos)t *= i+1;
		dp.resize(pos+1,t);
	}
	for(int i = pos+1;i<n;i++){
		rep(j,dp.size()){
		//	cout<<dp[j].val()<<' ';
		}
		//cout<<endl;
		if(s[i]=='1'){
			vector<mint> ndp(dp.size());
			rep(j,dp.size()){
				ndp[j] = dp[j] * (i-j);
			}
			dp = ndp;
			continue;
		}
		vector<mint> ndp(i+1);
		while(dp.size()!=ndp.size())dp.push_back(0);
		rep(j,dp.size()-1)ndp[j+1] += dp[j] * (j+1);
		rep(j,dp.size()-1){
			dp[j+1] += dp[j];
		}
		rep(j,dp.size()-1)ndp[j+1] += dp[j];
		dp = ndp;
	}
	mint ans = 0;
	rep(i,dp.size())ans += dp[i];
	cout<<ans.val()<<endl;
	return 0;
}