#include <iostream>

using namespace std;

int main()
{
    int a[10],i,n,suma=0,k=0;
    cin>>n;
    for(i=0;i<=n-1;i++){
        cout<<"nr=";
        cin>>a[i];
        if(a[i]>0) {
            suma=suma+a[i];
            k++;
        }
    }
    cout<<"Media aritmetica="<<(float)suma/k;
    return 0;
}