#include "bits/stdc++.h"
using namespace std;

constexpr long long MOD = 998244353;

int main() {
	int N;
	string S;
	cin >> N >> S;
	vector<int> P;
	for (int i = 1; i * i <= N; i++) {
		if (N % i == 0) {
			P.push_back(i);
			if (N / i != i) P.push_back(N / i);
		}
	}
	sort(P.begin(), P.end());
	vector<long long> ANS(N + 1);
	for (int L : P) {
		int X = N / L;
		if (X % 2 == 0) continue;
		string T = S.substr(0, L);
		long long COUNT = 0;
		for (int i = 0; i < L; i++) {
			COUNT *= 2;
			COUNT += T[i] - '0';
			COUNT %= MOD;
		}
		string U = "";
		for (int i = 0; i < N; i++) {
			if (i % (L * 2) < L) U += T[i % L];
			else U += T[i % L] ^ 1;
		}
		if (U <= S) COUNT++;
		COUNT %= MOD;
		ANS[L] = COUNT;
	}
	for (int L : P) {
		for (int K : P) {
			if (L > K&& L % K == 0) {
				ANS[L] += MOD - ANS[K];
				ANS[L] %= MOD;
			}
		}
	}
	long long SUM = 0;
	for (int L : P) {
		SUM += ANS[L] * L * 2;
		SUM %= MOD;
	}
	cout << SUM << endl;
}