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

int main()
{
	double height = 0,low = 0;
	double input;
	vector<double> height_array;
	do
	{
		cin >> input;
		height_array.push_back(input);
	} while (1);
	for (int i = 0;i < height_array.size();i++)
	{
		double temp;
		if (height < height_array[i]) {
			temp = height_array[i];
			height_array[i] = height;
			height = temp;
		}
		if (low > height_array[i])
		{
			low = height_array[i];
		}
	}
	cout << height - low << endl;
	return 0;
}