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#include<iostream>
#include<cstdio>
#include<algorithm>
using namespace std;
int main(){
int n,i;
float hello,t,sum;
while(cin>>n){
sum=0;
for(i=0;i<n;i++){
cin>>t;
sum+=t;
}
hello=sum/n;
printf("%.12lf\n",hello);
}
return 0;
}