import java.util.*;

public class Yukicoder_21{
	public static void main(String[] args){
		Scanner stdIn = new Scanner(System.in);
		int N = stdIn.nextInt();
		int K = stdIn.nextInt();
		int[] num = new int[N];
		for(int i=0;i<N;i++){
			num[i] = stdIn.nextInt();
		}
		Arrays.sort(num);
		System.out.println(num[N-1] - num[0]);
	}
}