3rd Balkan Olympiad in Informatics
Varna, Bulgaria, 5-11 October 1995

Day 1 - Problem 2 (Large numbers)

The positive integer number n is represented by k (40 <=k <= 80) digits in decimal system, and is called large number. The problem is to write a program that, for a given large number n determines the greatest integer such that p³+p²+3p<=n.

	Input: Program input will be in an ASCII file named INPUT.2 . The first line contains a large number n with k digits.
	Output: Output should be on the standard output (screen) and should contain the integer p only.
	Example: Input: 1000000000000001000000000000003000000000000001 Output: 1000000000000000