省赛热身赛之Median

原题：

Description

A median is described as the numeric value separating the higher half of a list, from the lower half. The median of a finite list of numbers can be found by arranging all the elements from lowest value to highest value and picking the middle one. If there is an even number of elements, the median is then defined to be the mean of the two middle values. Now, could you write a program to help to find the median?