#include<iostream>
using namespace std;

int main()
{
    double height;
    double max = 0.0, min = 10000000;
    while( cin >> height )
    {
        if( max < height )
            max = height;
        if( min > height )
            min = height;
    }
    cout << max - min << endl;

    return 0;
}
