#include<iostream>
using namespace std;

int main()
{
	double i, max = 0, min = 0;
	bool flag = true;

	while (cin >> i){
		if(flag){
			max = i;
			min = i;
			flag = false;
		}
		else{
			if (i < min)
				min = i;
			if (i > max)
				max = i;
		}
	}
	cout << max - min << endl;
	return 0;
}