#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
int main(){
	double h;
	vector<double> high;
	while(cin>>h){
		high.push_back(h);
	}
	sort(high.begin(),high.end());
	cout<<high[high.size()-1]-high[0]<<endl;
	return 0;
}