import java.util.Arrays;
import java.util.Scanner;
public class No0021 {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int k = sc.nextInt();
		int[] val = new int[n];
		for(int i=0; i<n; i++){
			val[i] = sc.nextInt();
		}
		Arrays.sort(val);
		System.out.println(val[n-1] - val[0]);
	}
}