#include<stdio.h>
int main()
{
    int n;
    scanf("%d",&n);
    if (n<=0)
    {
        printf("No readings provided\n");
        return 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;
}