#include <iostream>
#include <string>
#include <math.h>
#include <map>
#include <stdio.h>
#include <ctype.h>
#include <algorithm>
#include <stdlib.h>
#include <stack>
#include <queue>
#include <bitset>
#include <memory.h>

using namespace std;



int main() {
    
    double x;
    
    cin>>x;

    double hig=x;
    double low=x;
    
    
    while(cin>>x){
        if(hig<x)hig=x;
        if(low>x)low=x;
    }
    cout<<hig-low<<endl;
    return 0;
}