#include <iostream>
 
using namespace std;
 
int main(int argc, char **argv)
{
    double max, min, tmp;
     
    cin >> max;
    min = max;
     
    while(cin >> tmp){
        if(max < tmp){
            max = tmp;
        } else (tmp < min){
            min = tmp;
        }
    }
     
    cout << (double)(max - min) << endl;
     
    return 0;
}