func main()
	var l: int :: cui@inputInt()
	var r: int :: cui@inputInt()
	var c: int :: cui@inputInt()
	
	do r :: lib@min(r, l + 1000)
	
	var ans: int :: 1000
	for i(l, r)
		var cost: int :: i * c
		if(cost % 1000 = 0)
			do ans :: 0
		else
			do ans :: lib@min(ans, 1000 - cost % 1000)
		end if
	end for
	do cui@print("\{ans}\n")
end func