CF108B Datatypes

Tattah's youngest brother, Tuftuf, is new to programming. Since his older brother is such a good programmer, his biggest dream is to outshine him. Tuftuf is a student at the German University in Cairo (GUC) where he learns to write programs in Gava. Today, Tuftuf was introduced to Gava's unsigned integer datatypes. Gava has $ n $ unsigned integer datatypes of sizes (in bits) $ a_{1},a_{2},...\ a_{n} $ . The $ i $ -th datatype have size $ a_{i} $ bits, so it can represent every integer between $ 0 $ and $ 2^{a_{i}}-1 $ inclusive. Tuftuf is thinking of learning a better programming language. If there exists an integer $ x $ , such that $ x $ fits in some type $ i $ (in $ a_{i} $ bits) and $ x·x $ does not fit in some other type $ j $ (in $ a_{j} $ bits) where $ a_{i}<a_{j} $ , then Tuftuf will stop using Gava. Your task is to determine Tuftuf's destiny.

The first line contains integer $ n $ ( $ 2

Print "YES" if Tuftuf will stop using Gava, and "NO" otherwise.

In the second example, $ x=7 $ $ (111_{2}) $ fits in $ 3 $ bits, but $ x^{2}=49 $ $ (110001_{2}) $ does not fit in $ 4 $ bits.