import java.io.*;
import java.util.Arrays;

public class Test7 {
  public static void main(String[] args) throws IOException{
    BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
    String line;
    line=br.readLine();
    int n=Integer.parseInt(line);
    line=br.readLine();
    int k=Integer.parseInt(line);
    int[] data=new int[n];
    for(int i=0;i<n;i++){
      line=br.readLine();
      data[i]=Integer.parseInt(line);
    }
    Arrays.sort(data);
    System.out.println(data[n-1]-data[0]);
  }
}