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

public class No21{
	public static void main(String[] args) throws IOException{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		int n = Integer.parseInt(br.readLine());
		String k = br.readLine();
		int[] num = new int[n];
		for(int i=0; i < n; i++)
			num[i] = Integer.parseInt(br.readLine());
		Arrays.sort(num);
		System.out.println(num[n-1] - num[0]);
	}
}