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

int main()
{
    double height;
    vector<double> data;
    while(cin >> height)
    {
        data.push_back(height);
    }
    cout <<
        max_element(data.begin(),data.end())
        -
        min_element(data.begin(),data.end())
        << endl;

    return EXIT_SUCCESS;
}