#include <iostream>
#include <algorithm>
#include <limits>

using namespace std;

int main()
{
    double max_m, min_m, tmp;

    max_m = numeric_limits<double>::min();
    min_m = numeric_limits<double>::max();
    while (cin >> tmp) {
        max_m = max(max_m, tmp);
        min_m = min(min_m, tmp);
    }
    cout << max_m - min_m << endl;

    return 0;
}