#include<stdio.h>
int main()
{
    int size,ind ,sum=0;
    scanf("%d",&size);
    if(n<0||!scanf("%d",&size));
    {
        printf("Invalid input");
        return 0;
    }
    int arr[ind];
    for(ind=0;ind<size;ind++)
    {
        scanf("%d",&arr[ind]);
    }
    for(ind=0;ind<size;ind++)
    {
        int sum += arr[ind];
    }
    float avg=sum/size;
    printf("%.2f",float);
    return 0;
}