// editor5
#include <stdio.h>
int main(){
    int n;
    if(scanf("%d", &n)!=1){
    printf("No readings provided\n");
    return 0;
    }
    if(n<=0){
        printf("No readings provided\n");
        return 0;
        
    }
    int valu;
    double sum = 0;
    for (int i=0;i<n;i++){
        if(scanf("%d",&value)!= 1){
            printf("No readings provided\n");
            return 0;
        }
        sum +=value;
    }
    double avg =summ / n;
    printf("%.2f\n", avg);
    return 0;
}