Problem: Given an integer x, find 2 integers a and b such that: 

  * 1 ≤ a,b ≤ x 
  * b divides a (a is divisible by b). 
  * a ⋅ b>x. 
  * a/b<x. 

Input

The only line contains the integer x (1 ≤ x ≤ 100).

Output

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).

Examples

Input

10


Output

6 3

Input

1


Output

-1

Solution (in JAVA):

Solution:
import java.util.Scanner;
public class p1
{
	public static void main(String[] args)
	{
		Scanner sc=new Scanner(System.in);
		int a=sc.nextInt();
		int ans=0,ans1=0;
		int b=a+1;
		while(ans==0)
		{
			boolean flag=false;
			for(int i=2;i<b;i++)
			{
				if(b%i==0)
				{
					ans=i;
					flag=true;
					break;
				}
			}
			if(flag==true)
			{
				ans1=b/ans;
				if (ans1<ans) {
					int temp=ans1;
					ans1=ans;
					ans=ans1;
				}
				if ((ans1%ans)!=0) {
					ans=0;
					ans1=0;
					b=b+1;
				}
			}
			else
				b=b+1;
		}
		if((ans<=a) && (ans1<=a))
			System.out.print(ans1+" "+ans);
		else
			System.out.print(-1);

			
	}
}