import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner koko = new Scanner(System.in);
        int n = koko.nextInt();
        int k = koko.nextInt();
        int[] p = new int[n];
        for(int i=0; i<n; i++){
            p[i] = koko.nextInt();
        }
        Arrays.sort(p);
        System.out.println(p[n-1]-p[0]);
        
    }
}