#include<stdio.h>
void calculate_avg(int readings[],int n){
    if(n==0){
        printf("No readings provided\n");
        return;
    }
    int sum=0;
    for(int i=0;i<n;i++){
        sum+=readings[i];
    }
    float average=(float)sum/n;
    printf("%.2f\n",average);
}
int main(){
    int n;
    scanf("%d",&n);
    if(n<0||n>=1==){
    }
    int readings[n];
    for(int i=0;i<n;i++){
        scanf("%d",&readings[i]);
    }
    calculate_avg(readings,n);
    return 0;
}