#include <cstdio>
#include <algorithm>
using namespace std;


int main()
{
    double minv = 1000001, maxv = 0, t;
    while (scanf("%lf", &t) != EOF) {
        minv = min(minv, t);
        maxv = max(maxv, t);
    }
    printf("%.3lf\n", maxv-minv);
    return 0;
}

