#include<stdio.h>
int main(){
    int n;
    scanf("%d", &n);
    if(n <= 0){
        printf("No readings provided");
        return 0;
    }
    
int tem;
float sum = 0;
for(int i = 0;i < n;i++){
    scanf("%d", &  temp);
    sum += temp;
}
   float avg = sum / n;
   printf("%.2f" , avg);
   return 0;
}