#include<iostream>
#include<algorithm>
#include<vector>

using namespace std;

vector<double> mt;

int main() {
	
	double a;
	mt.clear();
	
	int b = 0;
	
	while( cin >> a)
	{
		mt.push_back(a);	
		b++;		
	}
	sort(mt.begin(), mt.end());
	cout << fixed << mt[b] - mt[0] << "\n";
	
	
	return 0;
}
