#include <iostream>
#include <fstream>
#include <math.h>

using namespace std;

double maksElem(double *ver, int& n) {
	double maks = 0;
	for (int i = 0; i < n; i++) {
		if (ver[i] > maks) {
			maks = ver[i];
		}
	}
	return maks;
}


int main(void) {
	setlocale(LC_ALL, "Russian");
	ifstream in("input2.dat");
	int n, x=7, count=0, counter=0;
	double b, maks, otv=0, del=12;
	in >> n;
	double* ver=new double[n];
	for (int i = 0; i < n; i++) {
		in >> b;
		ver[i] = b;
	}

	int i = 0;
	while (ver[i] == 0)
		i++;
	for (int j = i; j < n; j++) {
		count++;
		if (ver[j] != 0)
			counter++;
		if (ver[j] == 0 && ver[j + 1] == 0)
			break;
	}
	count++;
	counter++;

	if (count <= 7)
		x = counter;
	else {
		maks = maksElem(ver, n);
		while (otv != maks) {
			x++;
			otv = del / (x*x);
			otv = round(otv * 1000000) / 1000000;
		}
	}

	cout << x << endl;

	system("pause");
	return 0;
}