CF1088A Ehab and another construction problem

Given an integer $ x $ , find 2 integers $ a $ and $ b $ such that: - $ 1 \le a,b \le x $ - $ b $ divides $ a $ ( $ a $ is divisible by $ b $ ). - $ a \cdot b>x $ . - $ \frac{a}{b}

The only line contains the integer $ x $ $ (1 \le x \le 100) $ .

You should output two integers $ a $ and $ b $ , satisfying the given conditions, separated by a space. If no pair of integers satisfy the conditions above, print "-1" (without quotes).