#include<stdio.h>
void calculate avg(int readings[], int n) {
    if ( n==0) {
        printf("No readings provided\n");
        return;
    }
    int sum = 0;
    for (int i = 0; i < n; i++) {
        sum+=readings[i];
    }
    float average =(float)sum/n;
    printf("%.2f\n",average);
    
}
int main()  {
    int n;
    scanf("%d", &n);
    if(n < 0 || n>= 100) {
    }
    int readings[n];
    for (int i = 0; i < n; i++) {
        scanf("%d", &readings[i]);
    }
    calculate_avg(readings, n);
    return 0;
}