import java.util.*;

class Yuki21{
	public static void main(String[] args){
		Scanner stdIn = new Scanner(System.in);

		int num = stdIn.nextInt();
		int k = stdIn.nextInt();
		int[] n = new int[num];
		for(int i=0;i<num;i++){
			n[i] = stdIn.nextInt();
		}

		Arrays.sort(n);

		System.out.println((n[num-1]-n[0]));
		

	}
}