#include <bits/stdc++.h>
using namespace std ;
#define fast_input_output ios::sync_with_stdio(false); cin.tie(nullptr);
// #pragma GCC target("avx2")
// #pragma GCC optimize("O3")
#pragma GCC target("avx")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
typedef long long ll ;
typedef long double ld ;
typedef pair<ll,ll> P ;
typedef tuple<ll,ll,ll> TP ;
#define chmin(a,b) a = min(a,b)
#define chmax(a,b) a = max(a,b)
#define bit_count(x) __builtin_popcountll(x)
#define gcd(a,b) __gcd(a,b)
#define lcm(a,b) a / gcd(a,b) * b
#define rep(i,n) for(int i = 0 ; i < n ; i++)
#define rrep(i,a,b) for(int i = a ; i < b ; i++)
#define repi(it,S) for(auto it = S.begin() ; it != S.end() ; it++)
#define pt(a) cout << a << endl
#define DEBUG(...) ; cout << #__VA_ARGS__ << endl ; for(auto x : {__VA_ARGS__}) cout << x << "  " ; cout << endl ;
#define DEBUG_LIST(...) cout << #__VA_ARGS__ << endl ; DEBUG_REP(__VA_ARGS__) ;
#define DEBUG_REP(V) cout << "{ " ; repi(itr,V) cout << *itr << ", " ; cout << "}" << endl ;
#define debug(a) cout << #a << " " << a << endl
#define all(a) a.begin(), a.end()
#define endl "\n"

const int mod = 998244353 ;

template< int mod >
struct ModInt {
    int x;

    ModInt() : x(0) {}

    ModInt(int64_t y) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {}

    ModInt &operator+=(const ModInt &p) {
        if((x += p.x) >= mod) x -= mod;
        return *this;
    }

    ModInt &operator-=(const ModInt &p) {
        if((x += mod - p.x) >= mod) x -= mod;
        return *this;
    }

    ModInt &operator*=(const ModInt &p) {
        x = (int) (1LL * x * p.x % mod);
        return *this;
    }

    ModInt &operator/=(const ModInt &p) {
        *this *= p.inverse();
        return *this;
    }

    ModInt operator-() const { return ModInt(-x); }

    ModInt operator+(const ModInt &p) const { return ModInt(*this) += p; }

    ModInt operator-(const ModInt &p) const { return ModInt(*this) -= p; }

    ModInt operator*(const ModInt &p) const { return ModInt(*this) *= p; }

    ModInt operator/(const ModInt &p) const { return ModInt(*this) /= p; }

    bool operator==(const ModInt &p) const { return x == p.x; }

    bool operator!=(const ModInt &p) const { return x != p.x; }

    ModInt inverse() const {
        int a = x, b = mod, u = 1, v = 0, t;
        while(b > 0) {
            t = a / b;
            swap(a -= t * b, b);
            swap(u -= t * v, v);
        }
        return ModInt(u);
    }

    ModInt pow(int64_t n) const {
        ModInt ret(1), mul(x);
        while(n > 0) {
            if(n & 1) ret *= mul;
            mul *= mul;
            n >>= 1;
        }
        return ret;
    }

    friend ostream &operator<<(ostream &os, const ModInt &p) {
        return os << p.x;
    }

    friend istream &operator>>(istream &is, ModInt &a) {
        int64_t t;
        is >> t;
        a = ModInt< mod >(t);
        return (is);
    }

    static int get_mod() { return mod; }
};

using modint = ModInt< mod >;

modint powmod(modint x , ll n){
    modint res = 1 ;
    while(n > 0){
        if(n & 1) (res *= x);
        (x *= x);
        n >>= 1 ;
    }
    return res ;
}

int n;
string S;

int main(){
    // fast_input_output
    cin >> n >> S;
    vector<modint> A(n);
    rep(i,n) A[i] = S[i] - '0';
    modint res = 0;
    rrep(i,1,n+1){
        vector<vector<modint>> dp(n+1,vector<modint>(2,0));
        vector<vector<modint>> sp(n+1,vector<modint>(2,0));
        dp[0][0] = 1;
        sp[0][0] = 1;
        rrep(j,1,n+1){
            if(j-i>=0){
                dp[j][1] += sp[j-1][1];
                if(S[j-i] == '1'){
                    dp[j][1] += sp[j-i][0];
                    dp[j][0] += sp[j-1][0] - sp[j-i][0];
                }
                else{
                    dp[j][0] += sp[j-1][0];
                }
            }
            else{
                dp[j][0] += sp[j-1][0];
            }
            sp[j][1] = sp[j-1][1] + dp[j][1];
            sp[j][0] = sp[j-1][0] + dp[j][0];
        }
        res += dp[n][1] * powmod(2,i-1);
    }
    cout << res << endl;
}