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

int main(void){
	double tmp,cmax,cmin;
	cin >> tmp;
	cmax=cmin=tmp;
	while(cin >> tmp){
		if(cin.eof())
			break;
		cmax=max(cmax,tmp);
		cmin=min(cmin,tmp);
	}
	cout  << cmax-cmin << endl;
	return 0;
}