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

#define rep(i, N) for (int i = 0; i < N; i++)
typedef long long ll;
const int MOD = 1e9 + 7;
const ll INF = LLONG_MAX / 2;

int main() {
	int N; cin >> N;
	vector<int> a(N);
	rep(i, N) cin >> a[i];
	vector<double> F(1000 + 1);
	for (int n = 1; n <= 1000; n++) {
		double x = 0, y = 0;
		for (int i = 1; i <= n; i++)
			x += pow(0.81, i), y += pow(0.9, i);
		F[n] = sqrt(x) / y;
	}
	vector<double> f(N + 1);
	for (int n = 1; n <= N; n++)
		f[n] = (F[n] - F[1000]) / (F[1] - F[1000]) * 1200;
	double x = 0, y = 0;
	for (int i = 1; i <= N; i++) {
		x += pow(2, a[i - 1] / 800.0) * pow(0.9, i);
		y += pow(0.9, i);
	}
	double ans = log(x / y) / log(2) * 800 - f[N];
	cout << (int)ans << endl;
}