package backjoon;

// https://www.acmicpc.net/problem/1546

// 평균

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

import java.util.StringTokenizer;

public class _1546 {

public static void main(String[] args) throws IOException {

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

int cntSubject = Integer.parseInt(br.readLine());

StringTokenizer st = new StringTokenizer(br.readLine(), " ");

int max = 0;

// sol1. 배열사용

// memory 11912 runtime 88

/*

double[] arr = new double[cntSubject];

double newSum = 0;

// 최댓값 구하기

for(int i=0; i<cntSubject; i++){

arr[i] = Integer.parseInt(st.nextToken());

max = (int) Math.max(arr[i], max);

}

// 평균구하기

for(double score : arr){

newSum += score/max*100;

}

System.out.println(newSum/cntSubject);

*/

// sol2 배열사용하지않고 풀기

// memory 11780 runtime 84

double newSum = 0.0;

for (int i = 0; i < cntSubject; i++) {

int value = Integer.parseInt(st.nextToken());

if(value > max) {

max = value;

}

newSum += value;

}

System.out.println( ((newSum/max)*100.0)/cntSubject );

}

}

/*

input

3

40 80 60

output

75.0

input

5

1 2 4 8 16

output

38.75

*/