#include <stdio.h>
int main()
{
int n;
while (scanf("%d", &n) == 1)
{
float sum = 0.0f;
for (int i = 0; i < n; i++)
{
int a;
scanf("%d", &a);
sum += a;
}
printf("%.2f\n", sum / n);
}
return 0;
}