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

using namespace std;

int main()
{
	vector<double> mt;
	double m;
	int cont = -1;

	while(cin >> m){
		mt.push_back(m);
		cont++;
	}

	sort(mt.begin(), mt.end());

	cout << mt[cont] - mt[0] << endl;

	return 0;
}