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

int main() {
    int n;
    cin >> n;
    int64_t sum = 0;
    for (int i = 0; i < n; i++) {
        long double x;
        cin >> x;
        sum += x * 10000000000LL;
    }
    cout << fixed << setprecision(10) << 1.0 * sum / 10000000000LL << endl;
    return 0;
}