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 $b$ ).
• $a \cdot b>x$ .
• $\frac{a}{b}<x$ .

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).