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

using namespace std;

void solve()
{
	vector<double> mountain;
	double height;
	while(cin >> height)
	{
		mountain.push_back(height);
	}
	sort(mountain.begin(), mountain.end());
	cout << mountain[mountain.size() - 1] - mountain[0] << endl;
}

int main()
{
	solve();
	return(0);
}