import java.util.*;
class Main{
	public static void main(String[] args1) {
		Scanner s = new Scanner(System.in);
		String line = s.nextLine();
		String[] args = line.split(" ");
		int[] arr = new int[args.length];
		for(int i = 0;i < args.length;i++)
			arr[i] =  Integer.parseInt(args[i]);

		int count = 0;
		Arrays.sort(arr);
		for(int i = 0;i < arr.length-1;i++)
			count += Math.abs(arr[i] - arr[i+1]);

		System.out.println(count);


	}
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz