#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rrep(i, n) for (int i = (int)(n - 1); i >= 0; i--)
#define all(x) (x).begin(), (x).end()
#define sz(x) int(x.size())
using namespace std;
using ll = long long;
constexpr int INF = 1e9;
constexpr ll LINF = 1e18;
string YesNo(bool cond) {
    return cond ? "Yes" : "No";
}
string YESNO(bool cond) {
    return cond ? "YES" : "NO";
}
template <class T>
bool chmax(T& a, const T& b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}
template <class T>
bool chmin(T& a, const T& b) {
    if (b < a) {
        a = b;
        return true;
    }
    return false;
}
template <typename T, class F>
T bisect(T ok, T ng, const F& f) {
    while (abs(ok - ng) > 1) {
        T mid = min(ok, ng) + (abs(ok - ng) >> 1);
        (f(mid) ? ok : ng) = mid;
    }
    return ok;
}
template <typename T, class F>
T bisect_double(T ok, T ng, const F& f, int iter = 100) {
    while (iter--) {
        T mid = (ok + ng) / 2;
        (f(mid) ? ok : ng) = mid;
    }
    return ok;
}
template <class T>
vector<T> make_vec(size_t a) {
    return vector<T>(a);
}
template <class T, class... Ts>
auto make_vec(size_t a, Ts... ts) {
    return vector<decltype(make_vec<T>(ts...))>(a, make_vec<T>(ts...));
}
template <typename T>
istream& operator>>(istream& is, vector<T>& v) {
    for (int i = 0; i < int(v.size()); i++) {
        is >> v[i];
    }
    return is;
}
template <typename T>
ostream& operator<<(ostream& os, const vector<T>& v) {
    for (int i = 0; i < int(v.size()); i++) {
        os << v[i];
        if (i < sz(v) - 1) os << ' ';
    }
    return os;
}
#include <atcoder/modint>
using mint = atcoder::modint998244353;
#include <atcoder/fenwicktree>
int main() {
    int n;
    string s;
    cin >> n >> s;

    mint ans = 0;

    // 2^(d-1) の寄与を足す
    for (int d = 1; d <= n; d++) {
        atcoder::fenwick_tree<mint> dp(n + 1);
        dp.add(0, 1);
        for (int i = 1; i <= n; i++) {
            if (i - d >= 0 && s[i - d] == '1') {
                dp.add(i, dp.sum(i - d + 1, i));
            } else {
                dp.add(i, dp.sum(0, i));
            }
        }
        for (int i = 0; i + d <= n; i++) {
            if (s[i] == '1') {
                ans += dp.sum(0, i + 1) *
                       mint::raw(2).pow(max(0, n - 1 - (i + d))) *
                       mint::raw(2).pow(d - 1);
            }
        }
    }
    cout << ans.val() << '\n';
}