Drinks

题意翻译

题目描述： 小瓦斯雅有n杯橙汁饮料，第i杯饮料中橙汁所占体积分数为pi%，有一天，他决定做一杯混合饮料。他从每杯饮料中取相同比例的饮料并将它们混合在一起，然后他想知道混合饮料中含有多少橙汁。输出最终橙汁所占的体积分数。 输入描述： 第一行整数n，接下来n个整数pi 输出描述： 橙汁占的体积分数（当你输出的答案与标准答案绝对值相差不超过0.0001时，输出正确）

题目描述

Little Vasya loves orange juice very much. That's why any food and drink in his kitchen necessarily contains orange juice. There are $ n $ drinks in his fridge, the volume fraction of orange juice in the $ i $ -th drink equals $ p_{i} $ percent. One day Vasya decided to make himself an orange cocktail. He took equal proportions of each of the $ n $ drinks and mixed them. Then he wondered, how much orange juice the cocktail has. Find the volume fraction of orange juice in the final drink.

输入输出格式

输入格式

The first input line contains a single integer $ n $ ( $ 1<=n<=100 $ ) — the number of orange-containing drinks in Vasya's fridge. The second line contains $ n $ integers $ p_{i} $ ( $ 0<=p_{i}<=100 $ ) — the volume fraction of orange juice in the $ i $ -th drink, in percent. The numbers are separated by a space.

输出格式

Print the volume fraction in percent of orange juice in Vasya's cocktail. The answer will be considered correct if the absolute or relative error does not exceed $ 10^{-4} $ .

输入输出样例

输入样例 #1

3
50 50 100

输出样例 #1

66.666666666667

输入样例 #2

4
0 25 50 75

输出样例 #2

37.500000000000

说明

Note to the first sample: let's assume that Vasya takes $ x $ milliliters of each drink from the fridge. Then the volume of pure juice in the cocktail will equal  milliliters. The total cocktail's volume equals $ 3·x $ milliliters, so the volume fraction of the juice in the cocktail equals , that is, $ 66.(6) $ percent.