import std.stdio,std.string,std.conv,std.algorithm;

int main()
{
	string s;
	double Max,Min;
	bool flag = true;
	while((s = readln.chomp).length != 0)
	{
		double a = s.to!double;
		if(flag)
		{
			Max = a;
			Min = a;
			flag = false;
		}
		else
		{
			Max = max(Max,a);
			Min = min(Min,a);
		}
	}
	writeln(Max-Min);
	return 0;
}