/* package whatever; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
    public static void main (String[] args) throws java.lang.Exception
    {
        // your code goes here
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int n = Integer.parseInt(br.readLine());
        int k = Integer.parseInt(br.readLine());
        int max = Integer.MIN_VALUE;
        int min = Integer.MAX_VALUE;
        for(int i=0;i<n;i++){
            String line = br.readLine();
            max = Math.max(max,Integer.parseInt(line));
            min = Math.min(min,Integer.parseInt(line));
        }
        System.out.println(max-min);
    }
}