#include <bits/stdc++.h>
using namespace std;
template <typename T>
T inverse(T a, T m) {
  T u = 0, v = 1;
  while (a != 0) {
    T t = m / a;
    m -= t * a; swap(a, m);
    u -= t * v; swap(u, v);
  }
  assert(m == 1);
  return u;
}
template <typename T>
class Modular {
 public:
  using Type = typename decay<decltype(T::value)>::type;
  constexpr Modular() : value() {}
  template <typename U>
  Modular(const U& x) {
    value = normalize(x);
  }
  template <typename U>
  static Type normalize(const U& x) {
    Type v;
    if (-mod() <= x && x < mod()) v = static_cast<Type>(x);
    else v = static_cast<Type>(x % mod());
    if (v < 0) v += mod();
    return v;
  }
  const Type& operator()() const { return value; }
  template <typename U>
  explicit operator U() const { return static_cast<U>(value); }
  constexpr static Type mod() { return T::value; }
  Modular& operator+=(const Modular& other) { if ((value += other.value) >= mod()) value -= mod(); return *this; }
  Modular& operator-=(const Modular& other) { if ((value -= other.value) < 0) value += mod(); return *this; }
  template <typename U> Modular& operator+=(const U& other) { return *this += Modular(other); }
  template <typename U> Modular& operator-=(const U& other) { return *this -= Modular(other); }
  Modular& operator++() { return *this += 1; }
  Modular& operator--() { return *this -= 1; }
  Modular operator++(int) { Modular result(*this); *this += 1; return result; }
  Modular operator--(int) { Modular result(*this); *this -= 1; return result; }
  Modular operator-() const { return Modular(-value); }
  template <typename U = T>
  typename enable_if<is_same<typename Modular<U>::Type, int>::value, Modular>::type& operator*=(const Modular& rhs) {
    value = normalize(static_cast<int64_t>(value) * static_cast<int64_t>(rhs.value));
    return *this;
  }
  template <typename U = T>
  typename enable_if<is_same<typename Modular<U>::Type, int64_t>::value, Modular>::type& operator*=(const Modular& rhs) {
    int64_t q = static_cast<int64_t>(static_cast<long double>(value) * rhs.value / mod());
    value = normalize(value * rhs.value - q * mod());
    return *this;
  }
  template <typename U = T>
  typename enable_if<!is_integral<typename Modular<U>::Type>::value, Modular>::type& operator*=(const Modular& rhs) {
    value = normalize(value * rhs.value);
    return *this;
  }
  Modular& operator/=(const Modular& other) { return *this *= Modular(inverse(other.value, mod())); }
  template <typename U>
  friend const Modular<U>& abs(const Modular<U>& v) { return v; }
  template <typename U>
  friend bool operator==(const Modular<U>& lhs, const Modular<U>& rhs);
  template <typename U>
  friend bool operator<(const Modular<U>& lhs, const Modular<U>& rhs);
  template <typename U>
  friend std::istream& operator>>(std::istream& stream, Modular<U>& number);
 private:
  Type value;
};
template <typename T> bool operator==(const Modular<T>& lhs, const Modular<T>& rhs) { return lhs.value == rhs.value; }
template <typename T, typename U> bool operator==(const Modular<T>& lhs, U rhs) { return lhs == Modular<T>(rhs); }
template <typename T, typename U> bool operator==(U lhs, const Modular<T>& rhs) { return Modular<T>(lhs) == rhs; }
template <typename T> bool operator!=(const Modular<T>& lhs, const Modular<T>& rhs) { return !(lhs == rhs); }
template <typename T, typename U> bool operator!=(const Modular<T>& lhs, U rhs) { return !(lhs == rhs); }
template <typename T, typename U> bool operator!=(U lhs, const Modular<T>& rhs) { return !(lhs == rhs); }
template <typename T> bool operator<(const Modular<T>& lhs, const Modular<T>& rhs) { return lhs.value < rhs.value; }
template <typename T> Modular<T> operator+(const Modular<T>& lhs, const Modular<T>& rhs) { return Modular<T>(lhs) += rhs; }
template <typename T, typename U> Modular<T> operator+(const Modular<T>& lhs, U rhs) { return Modular<T>(lhs) += rhs; }
template <typename T, typename U> Modular<T> operator+(U lhs, const Modular<T>& rhs) { return Modular<T>(lhs) += rhs; }
template <typename T> Modular<T> operator-(const Modular<T>& lhs, const Modular<T>& rhs) { return Modular<T>(lhs) -= rhs; }
template <typename T, typename U> Modular<T> operator-(const Modular<T>& lhs, U rhs) { return Modular<T>(lhs) -= rhs; }
template <typename T, typename U> Modular<T> operator-(U lhs, const Modular<T>& rhs) { return Modular<T>(lhs) -= rhs; }
template <typename T> Modular<T> operator*(const Modular<T>& lhs, const Modular<T>& rhs) { return Modular<T>(lhs) *= rhs; }
template <typename T, typename U> Modular<T> operator*(const Modular<T>& lhs, U rhs) { return Modular<T>(lhs) *= rhs; }
template <typename T, typename U> Modular<T> operator*(U lhs, const Modular<T>& rhs) { return Modular<T>(lhs) *= rhs; }
template <typename T> Modular<T> operator/(const Modular<T>& lhs, const Modular<T>& rhs) { return Modular<T>(lhs) /= rhs; }
template <typename T, typename U> Modular<T> operator/(const Modular<T>& lhs, U rhs) { return Modular<T>(lhs) /= rhs; }
template <typename T, typename U> Modular<T> operator/(U lhs, const Modular<T>& rhs) { return Modular<T>(lhs) /= rhs; }
template<typename T, typename U>
Modular<T> power(const Modular<T>& a, const U& b) {
  assert(b >= 0);
  Modular<T> x = a, res = 1;
  U p = b;
  while (p > 0) {
    if (p & 1) res *= x;
    x *= x;
    p >>= 1;
  }
  return res;
}
template <typename T>
bool IsZero(const Modular<T>& number) {
  return number() == 0;
}
template <typename T>
string to_string(const Modular<T>& number) {
  return to_string(number());
}
template <typename T>
std::ostream& operator<<(std::ostream& stream, const Modular<T>& number) {
  return stream << number();
}
template <typename T>
std::istream& operator>>(std::istream& stream, Modular<T>& number) {
  typename common_type<typename Modular<T>::Type, int64_t>::type x;
  stream >> x;
  number.value = Modular<T>::normalize(x);
  return stream;
}
constexpr int md = 998244353;
using Mint = Modular<std::integral_constant<decay<decltype(md)>::type, md>>;
template <typename... Args> void read(Args &... args) { (cin >> ... >> args); }
template <typename... Args> void writeln(const Args &... args) { ((cout << args << " "), ...), cout << "\n"; }
template <typename... Args> void write(const Args &... args) { ((cout << args), ...); }
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
template <typename T> typename enable_if<is_same<decltype(declval<T>().size()), size_t>::value, int>::type operator~(const T &ct) { return (int)ct.size(); }
template <typename T, typename... Args> bool ckmax(T &a, const Args &... b) { return (a < max({b...})) ? (a = max({b...}), true) : false; }
template <typename T, typename... Args> bool ckmin(T &a, const Args &... b) { return (a > min({b...})) ? (a = min({b...}), true) : false; }
template <typename T> struct range { T u, v; bool inclusive;
    range(const T &_u, const T &_v, const bool &_inclusive = false)
        : u(_u), v(_v), inclusive(_inclusive) {}
    bool has(const T &w) { return (u <= w) and (inclusive ? (w <= v) : (w < v)); }
};
using vi = vector<int>;
using vb = vector<bool>;
using pii = pair<int, int>;
using vvi = vector<vector<int>>;
using vpii = vector<pii>;
using uint = unsigned;
using ll = long long;
using ull = unsigned long long;
using ld = long double;
using vll = vector<ll>;
using pll = pair<ll, ll>;
using vpll = vector<pll>;
template <typename T> using vv = vector<vector<T>>;
template <typename T> using min_heap = priority_queue<T, vector<T>, greater<T>>;
template <typename T> using max_heap = priority_queue<T, vector<T>, less<T>>;
const int N = 200'010;
vi odd_divs(int n) {
    vi res;
    for (int i = 1; i <= n; ++i) {
        if (!(n % i) and i % 2) {
            res.push_back(i);
        }
    }
    return res;
}
Mint bintuMintu(const string& s) {
    Mint res = 0;
    for(int i = 0; i < ~s; ++i) {
        res = 2*res + (s[i] - '0');
    }
    ;;
    return res;
}
Mint compute(int hf, int d, const string& x){
    int n = ~x;
    string s = x.substr(0, hf), t(hf, '0');
    for(int i = 0; i < ~s; ++i){
        t[i] = s[i] ^ 1;
    }
    ;;
    Mint res = bintuMintu(s);
    string st;
    for(int i = 0; i < (d >> 1); ++i) {
        st += s, st+=t;
    }
    st += s;
    res += (st <= x);
    return res;
}
auto soln() {
    int n;
    string x;
    cin >> n >> x;
    map<int, Mint> C;
    for(auto d : odd_divs(n)){
        int hf = n/d, k = 2*hf;
        C[k] = compute(hf, d, x);
    }
    ;;
    for(int i = 1; i <= n; ++i){
        if(C.find(i) != C.end()){
            for(int j = 2*i; j <= 2*n; j += i){
                if(C.find(j) != C.end()) C[j] -= C[i];
            }
        }
    }
    ;;
    Mint res;
    for (auto &[k, v] : C) {
        res += k*v;
    }
    cout << res << "\n";
}
signed main() {
    int t = 1;
    { ios_base::sync_with_stdio(false), cin.tie(NULL), cout.tie(NULL); }
    while (t--)
        soln();
    return 0;
}


Measured memory_bytes: 4196