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

int main(){
    double n;
    vector<double> v;
    while( cin >> n ){
        v.push_back( n );
    }
    double a = v[0];
    double b = v[0];
    for(int i=0 ; i < v.size() ; i++ ){
        a = max( a , v[i] );
        b = min( b , v[i] );
    }
    cout << (a-b) << endl;
}