#include <bits/stdc++.h>

using namespace std;

int main() {
    double m, maxm = 0.0, minm = 1000000.0;
    while (scanf("%lf", &m) != EOF) {
        if (m > maxm) maxm = m;
        if (m < minm) minm = m;
    }
    cout << maxm - minm << endl;

    return 0;
}
