#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
int main(){
	double a;
	int i=0;
	vector <double> data;
	while(cin>>a){
		data[i]=a;
		i++;
	}
	sort(data.begin(),data.end());
	cout<<data[i-1]-data[0]<<endl;
	return 0;
}