include <bits/stdc++.h>

using namespace std;

int main() {

double a, b, c, e, d = 0;
scanf("%lf", &a);
c = a;
for (e = 1; e <= a; e++) {
	scanf("%lf", &b);
	d += b;
}
d /= c;
printf("%.2lf", d);
return 0;

}