#include <iostream>
#include <cstdlib>
#include <vector>
#include <algorithm>
#include <iomanip>
using namespace std;

int main()
{
    double height;
    double ans;
    vector<double> data;
    vector<double>::iterator itMax, itMin;
    while(cin >> height)
    {
        data.push_back(height);
    }
    cout << setprecision(3) << fixed;
    ans = *(max_element(data.begin(),data.end()))
        - *(min_element(data.begin(),data.end()));
    cout << ans << endl;

    return EXIT_SUCCESS;
}