import java.util.Scanner;

public class AverageDiff {

	public static void main(String[] args) {
		// 標準入力から読み込む際に、Scannerオブジェクトを使う。
        Scanner sc = new Scanner(System.in);
        int a = sc.nextInt();
        int b = sc.nextInt();
    	int c = 0;
    	int min = 1000;
    	int max = 0;
    	
        for (int i=0;i<a;i++) {
        	c = sc.nextInt();
        	if (min > c) min = c; 
        	if (max < c) max = c; 
        }
        System.out.println(max-min);
	}

}