#include <iostream>

using namespace std;

int main(void) {
    double h, max_h = 0, min_h = 1e100;
    while (true) {
        cin >> h;
        if (h > max_h) max_h = h;
        else if (h < min_h) min_h = h;
        if (cin.eof()) break;
    }
    cout << (max_h - min_h) << endl;
    return 0;
}