#include <iostream>
#include <vector>
#include <algorithm>
#include <functional>
using namespace std;

int main()
{
    double h,ans;
    vector<double> mh;
    while(cin>>h)
    {
        mh.push_back(h);
    }
    sort(mh.begin(),mh.end(),greater<double>());
    cout<<*mh.begin()-*(mh.end()-1)<<endl;
}