#include <iostream>

#include <sstream>

using namespace std;

int solution(vector<int> &A) {

    int n = A.size();

    int prevPeak = -1;

    int maxDist = -1;

    vector<int> peaks(n);

    for (int i = 0; i < n; i++) {

        if (i == 0) {

            peaks[i] = 0;

        } else if (i == n - 1) {

            peaks[i] = peaks[i - 1];

        } else if (A[i] > A[i - 1] && A[i] > A[i + 1]) {

            peaks[i] = peaks[i - 1] + 1;

            if (prevPeak == -1) {

                prevPeak = i;

            } else {

                maxDist = max(maxDist, i - prevPeak);

                prevPeak = i;

            }

        } else {

            peaks[i] = peaks[i - 1];

        }

    }

    if (peaks[n - 1] == 0) return 0;

    if (peaks[n - 1] == 1) return 1;

    for (int dist = maxDist / 2; dist <= n; dist++) {

        if (n % dist != 0)

            continue;

        bool found = true;

        for (int i = n - 1; i - dist > 0; i -= dist) {

            if (peaks[i] == peaks[i - dist]) {

                found = false;

                break;

            }

        }

        if (found) return n / dist;

    }

    return 0;

}