// (⁠◕⁠ᴗ⁠◕⁠✿⁠)
 
#include <bits/stdc++.h>
#define rep(i, n) for (ll i = 0; i < (n); i++)
#define srep(i, s, n) for (ll i = s; i < (n); i++)
#define len(x) ((int)(x).size())
#define all(x) (x).begin(), (x).end()
using namespace std;
template<typename T> using vc = vector<T>;
template<typename T> using vv = vc<vc<T>>;
template<typename T> using vvv = vv<vc<T>>;
using vi = vc<int>;using vvi = vv<int>; using vvvi = vv<vi>;
using ll = long long;using vl = vc<ll>;using vvl = vv<ll>; using vvvl = vv<vl>;
using ld = long double; using vld = vc<ld>; using vvld = vc<vld>; using vvvld = vc<vvld>;
using uint = unsigned int;
using ull = unsigned long long;
const ld pi = 3.141592653589793;
const int inf = 0x3f3f3f3f;
const ll INF = 0x3f3f3f3f3f3f3f3f;
// const ll mod = 1000000007;
const ll mod = 998244353;
inline bool inside(long long y, long long x, long long H, long long W) {return 0 <= (y) and (y) < (H) and 0 <= (x) and (x) < (W); }

#define debug(var)  do{std::cout << #var << " : \n";view(var);}while(0)
template<typename T> void view(T e){cout << e << endl;}
template<typename T> void view(const vc<T>& v){for(const auto& e : v){ cout << e << " "; } cout << endl;}
template<typename T> void view(const vv<T>& vv){ for(const auto& v : vv){ view(v); } }

template<ll Mod> struct modint {
    ll val;
    using mint = modint;
    modint() {};
    modint(ll v) {
        if (0 <= v && v < Mod) val = v;
        else{
            v %= Mod;
            if (v < 0) v += Mod;
            val = v;
        }
    }
    mint operator++(int){
        val++;
        if (val == Mod) val = 0;
        return *this;
    }
    mint operator--(int){
        if (val == 0) val = Mod;
        val--;
        return *this;
    }
    mint& operator+=(const mint& v){
        val += v.val;
        if (val >= Mod) val -= Mod;
        return *this;
    }
    friend mint operator+(const mint& u, const mint& v){
        return mint(u) += v;
    }
    mint& operator-=(const mint& v){
        val -= v.val;
        if (val < 0) val += Mod;
        return *this;
    }
    friend mint operator-(const mint& u, const mint& v){
        return mint(u) -= v;
    }
    mint& operator*=(const mint& v){
        val *= v.val;
        if (val >= Mod) val %= Mod;
        return *this;
    }
    friend mint operator*(const mint& u, const mint& v){
        return mint(u) *= v;
    }
    mint pow(ll n){
        mint a = *this, ret = 1;
        while (n > 0){
            if (n & 1) ret *= a;
            a *= a;
            n >>= 1;
        }
        return ret;
    }
    mint operator/=(const mint& v){
        val *= mint(v).pow(Mod - 2).val;
        if (val >= Mod) val %= Mod;
        return *this;
    }
    friend mint operator/(const mint& u, const mint& v){
        return mint(u) /= v;
    }
    friend bool operator==(const mint& u, const mint& v){
        return u.val == v.val;
    }
    friend bool operator!=(const mint& u, const mint& v){
        return u.val != v.val;
    }
    friend bool operator>(const mint& u, const mint& v){
        return u.val > v.val;
    }
    friend bool operator<(const mint& u, const mint& v){
        return u.val < v.val;
    }
};

using mint = modint<mod>;

int main(){
    int N; cin >> N;
    string S; cin >> S;
    while (S.back() == '0')S.pop_back();
    if (S == ""){
        cout << 0 << endl;
        return 0;
    }
    reverse(all(S));
    mint ret = 1;
    ll cnt = 0;
    for (auto s : S){
        if (s == '1'){
            ret *= (cnt + 1);
            cnt = 1;
        }else cnt++;
    }
    cout << ret.val << endl;
}