import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.*;
import java.math.*;
 
public class Main {
	public static void main(String[] args)throws IOException{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		StringBuilder sb = new StringBuilder();
		int n = Integer.parseInt(br.readLine());
		int k = Integer.parseInt(br.readLine());
		int[] a = new int[n];
		for(int i = 0; i < n; i++){
			a[i] = Integer.parseInt(br.readLine());
		}
		Arrays.sort(a);
		sb.append(a[n-1]-a[0]);
		System.out.println(sb);
	}
}