import std.stdio : readln, writeln, chomp, stdin;
import std.conv : to;
import std.algorithm : min, max;

void solve()
{
	double V=0;
	double M=cast(double)(1<<28);
	while(true){
		string str = readln.chomp;
		
		if(stdin.eof())	break;
		
		double d = str.to!double;
		V = max(d, V);
		M = min(d, M);
	}
	writeln = V-M;
}

void main()
{
	solve();
}