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