#ifdef MAIN 
bool __multi__ = 0;

namespace XK {
const ll mod = 998244353;
struct mm {
   ll x;
   mm(ll x_ = 0) : x(x_ % mod) {
      if(x < 0) x += mod;
   }
   friend mm operator+(mm a, mm b) { return a.x + b.x; }
   friend mm operator-(mm a, mm b) { return a.x - b.x; }
   friend mm operator*(mm a, mm b) { return a.x * b.x; }
   friend mm operator/(mm a, mm b) { return a * b.inv(); }
   friend mm& operator+=(mm& a, mm b) { return a = a.x + b.x; }
   friend mm& operator-=(mm& a, mm b) { return a = a.x - b.x; }
   friend mm& operator*=(mm& a, mm b) { return a = a.x * b.x; }
   friend mm& operator/=(mm& a, mm b) { return a = a * b.inv(); }
   mm inv() const { return pow(mod - 2); }
   mm pow(ll b) const {
      mm a = *this, c = 1;
      while(b) {
         if(b & 1) c *= a;
         a *= a;
         b >>= 1;
      }
      return c;
   }
};


  void solve() {
  	int N; cin >> N; string S; cin >> S;
  	V<V<mm>> f(N, V<mm>(N + 1, 0));
  	if(S[0] == '1') f[0][0] = N;
  	else rep(i, N + 1) f[0][i] = 1;
  	Rep(i, 1, N) {
  		if(S[i] == '1') {
  			rep(j, N + 1) if(i + j < N) f[i][j] += f[i - 1][j] * (N - i - j);
  		} else {
  			auto nf = f[i - 1];
  			Rep(j, 1, N + 1) nf[j] += nf[j - 1];
  			rep(j, N + 1) f[i][j] += nf[j];
  			Rep(j, 1, N + 1) f[i][j - 1] += f[i - 1][j] * j;
#ifdef DEBUG 
  			cout << "nf: "; rep(k, N + 1) cout << nf[k].x << ' '; cout << '\n';
  			cout << "f: "; rep(k, N + 1) cout << f[i][k].x << ' '; cout << '\n';
#endif
  		}
  	}
  	cout << f[N - 1][0].x;

  }
};

#else
#include "cassert"
#include "cmath"
#include "cstdint"
#include "cstdio"
#include "cstdlib"
#include "cstring"
#include "algorithm"
#include "bitset"
#include "chrono"
#include "complex"
#include "deque"
#include "functional"
#include "iostream"
#include "limits"
#include "map"
#include "numeric"
#include "queue"
#include "random"
#include "set"
#include "sstream"
#include "string"
#include "unordered_map"
#include "unordered_set"
#include "utility"
#include "vector"
#include "array"
using namespace std;
#define int long long
using ll = long long;
using ull = unsigned long long;
const ll INF = 1ll << 60;
const ll LINF = 0x1fffffffffffffff;
const ll MINF = 0x7fffffffffff;
template <class A, class B> bool chmax(A& l, const B& r){ return r > l ? l = r, 1 : 0; }
template <class A, class B> bool chmin(A& l, const B& r){ return r < l ? l = r, 1 : 0; }
#define sz(x) ssize(x)
#define rep(i, a) for(ll i = 0; i < (a); i ++)
#define Rep(i, a, b) for(ll i = (a); i < (b); i ++)
#define rrep(i, a, b) for(ll i = (b); i --> (a); )
#define all(x) begin(x), end(x)
#define fst first
#define snd second
#define pb push_back
template<class T> using V = vector<T>;
template<class T, std::size_t N> using AR = array<T, N>;
#define MAIN
#include __FILE__
signed main() {ios::sync_with_stdio(0);cin.tie(0);fixed(cout).precision(12);int t = 1;if(__multi__) cin >> t;while(t --) XK::solve();}
#endif