import java.util.Scanner;
import java.util.Arrays;

class Test {
	public static void main(String[] args) throws Exception {
		Scanner in = new Scanner(System.in);

		int N = in.nextInt();
		int K = in.nextInt();
		int [] nn = new int[N];

		for(int i=0; i<N; i++) {
			nn[i] = in.nextInt();
		}

		Arrays.sort(nn);

		System.out.println(nn[N - 1] - nn[0]);
	}
}