#include<iostream>
#include<cmath>
#include<iomanip>
#include<algorithm>
#include<cstdlib>
#include<cstring>
#include<vector>

#define ll long long
#define sz(x) int(x.size())
#define all(x) x.begin(),x.end()
using namespace std;

void Fast_IO(){
    ios_base::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
    #ifndef ONLINE_JUDGE
        freopen("input.txt", "r", stdin), freopen("output.txt","w", stdout);
    #endif
}

 int n;
 ll arr[105];
double avg(ll idx, double result){
if(idx == n) return result/n;
return avg(idx+1,result+=arr[idx]);
}

void solve(){
cin>>n;
for(int i =0; i<n; i++) cin>>arr[i];

cout<<fixed<<setprecision(6);
cout<<avg(0,0);

}

int main(){
    Fast_IO();
int t =1;
//cin>>t;
while(t--){
solve();
}
return 0;
}