#include <iostream>
#include <algorithm>
using namespace std;

#define N 5
int main(){
	double height[N];
	
	for(int i=0;i<N;i++){
		cin >> height[i];
	}
	
	sort(height,height+N);
	
	double heightd = height[N-1] - height[0];
	cout << heightd << endl;
	
	return 0;
}