#include <bits/stdc++.h>
#define FOR(i, a, n) for(ll i = (ll)a; i < (ll)n; i++)
#define rep(i, n) FOR(i, 0, n)
#define ALL(x) (x).begin(), (x).end()
using namespace std;
typedef long long ll;

constexpr ll Mod = 998244353;
constexpr ll mod = 1e9 + 7;
constexpr ll inf = 1LL << 60;

template <typename T> constexpr bool chmax(T &a, const T b) {
    if(a >= b) return false;
    a = b;
    return true;
}
template <typename T> constexpr bool chmin(T &a, const T b) {
    if(a <= b) return false;
    a = b;
    return true;
}

/*-------------------------------------------*/

template <int M> class ModInt {
    int x;

  public:
    constexpr ModInt() : x(0) {}
    constexpr ModInt(int64_t y) : x(y >= 0 ? y % M : (M - (-y) % M) % M) {}
    constexpr ModInt &operator+=(const ModInt &p) {
        if((x += p.x) >= M) x -= M;
        return *this;
    }
    constexpr ModInt &operator-=(const ModInt &p) {
        if((x += M - p.x) >= M) x -= M;
        return *this;
    }
    constexpr ModInt &operator*=(const ModInt &p) {
        x = (int)(1LL * x * p.x % M);
        return *this;
    }
    constexpr ModInt &operator/=(const ModInt &p) {
        *this *= p.inverse();
        return *this;
    }
    constexpr ModInt operator-() const { return ModInt(-x); }
    constexpr ModInt operator+(const ModInt &p) const {
        return ModInt(*this) += p;
    }
    constexpr ModInt operator-(const ModInt &p) const {
        return ModInt(*this) -= p;
    }
    constexpr ModInt operator*(const ModInt &p) const {
        return ModInt(*this) *= p;
    }
    constexpr ModInt operator/(const ModInt &p) const {
        return ModInt(*this) /= p;
    }
    constexpr bool operator==(const ModInt &p) const { return x == p.x; }
    constexpr bool operator!=(const ModInt &p) const { return x != p.x; }
    constexpr ModInt inverse() const {
        int a = x, b = M, u = 1, v = 0, t = 0;
        while(b > 0) {
            t = a / b;
            swap(a -= t * b, b);
            swap(u -= t * v, v);
        }
        return ModInt(u);
    }
    constexpr 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;
    }
    constexpr friend ostream &operator<<(ostream &os, const ModInt &p) {
        return os << p.x;
    }
    constexpr friend istream &operator>>(istream &is, ModInt &a) {
        int64_t t = 0;
        is >> t;
        a = ModInt(t);
        return (is);
    }
};
using modint = ModInt<Mod>;

int main() {
    cin.tie(0);
    ios::sync_with_stdio(0);

    int n;
    string s;
    cin >> n >> s;

    vector<int> v;
    int m = 2 * n;
    FOR(i, 1, m + 1) {
        if(m % i == 0 && (m / i) % 2 == 1) {
            v.push_back(i);
        }
    }

    string t = s;
    rep(i, n) t.push_back('0' + '1' - s[i]);
    vector<modint> cnt;
    for(int k : v) {
        modint a;
        rep(i, k / 2) {
            a *= modint(2);
            if(s[i] == '1') a += modint(1);
        }
        string str = s.substr(0, k / 2);
        rep(i, k / 2) str.push_back('0' + '1' - str[i]);
        while(str.size() < t.size())
            str += str.substr(0, k);
        if(str <= t) a += 1;
        cnt.push_back(a);
    }

    rep(i, cnt.size()) FOR(j, i + 1, cnt.size()) if(v[j] % v[i] == 0) cnt[j] -=
        cnt[i];

    modint ans(0);
    rep(i, cnt.size()) ans += cnt[i] * modint(v[i]);

    cout << ans << endl;

    return 0;
}

Measured memory_bytes: 2068