#include <bits/stdc++.h>
using namespace std;

int main() {
	ios_base::sync_with_stdio( false );

	double high = 0;
	double low = DBL_MAX;

	double x;
	while( cin >> x ) {
		if( x > high ) { high = x; }
		if( x < low ) { low = x; }
	}

	cout << fixed << setprecision( 2 ) << (high - low) << endl;
	return 0;
}

