#include <bits/stdc++.h>

using namespace std;
typedef long long ll;

#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rep2(i, s, n) for (int i = (s); i < (int)(n); i++)
#define DEBUG

int main()
{
    int n;
    const ll f = 10e10;
    double a, ans;
    ll s, sum;
    sum = 0;
    cin >> n;
    rep(i, n){
        cin >> s;
        sum += s * f;
    }
    ans = sum / f;
    printf( "%.10f\n", ans );
    
    
    return 0;
}