import java.util.Scanner;

public class Main{
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int g = sc.nextInt();
		int[] a = new int[n];
		for(int i=0;i<n;i++) {
			a[i] = sc.nextInt();
		}

		for(int i=0;i<n;i++) {
			for(int j=a.length-1;j>0+i;j--) {
				if(a[j]>a[j-1]) {
					int temp = a[j];
					a[j] = a[j-1];
					a[j-1] = temp;
				}
			}
		}
		System.out.println(a[0]-a[a.length-1]);

	}
}