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

const int INF = 1 << 25;

int main()
{
	double max_ = -1, min_ = INF;
	double r;
	while(cin >> r){
		max_ = max(max_,r);
		min_ = min(min_,r);
	}
	
	cout << max_ - min_ << endl;
}