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