import java.io.IOException;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.Arrays;

class Main{
    public static void main(String[] args) throws IOException{
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int n = Integer.parseInt(br.readLine());
        int k = Integer.parseInt(br.readLine());
        int[] arr = new int[n];
        for(int i = 0; i < n; i++){
            arr[i] = Integer.parseInt(br.readLine());
        }
        Arrays.sort(arr);

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