#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

double F(int n){
	double a = 0, b = 0;
	double c = 0.81, d = 0.9;
	for(int i = 0; i < n; i++) {
		a += c;
		b += d;
		c *= 0.81;
		d *= 0.9;
	}
	return sqrt(a) / b;
}

double f(int n){
	return 1200 * (F(n) - F(1000000)) / (F(1) - F(1000000));
}

double g(double X){
	return pow(2, X / 800.0);
}

double R[100];

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

	int N;
	cin >> N;
	for(int i = 0; i < N; i++) {
		cin >> R[i];
	}

	double a = 0, b = 0;
	double c = 0.9;
	for(int i = 0; i < N; i++) {
		a += g(R[i]) * c;
		b += c;
		c *= 0.9;
	}

	double t1 = 800 * (log2(a) - log2(b)), t2 = f(N);
	cout << (int)round(t1 - t2) << endl;
}