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

void main(){

    real maxm,minm;
    maxm = 0;
    minm = 200000000;
    while(true){
	auto s = readln();
	if(stdin.eof()) break;
	real n = to!real(chomp(s));
	maxm = max(maxm,n);
	minm = min(minm,n);
    }
    writeln(maxm-minm);
}