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.*;

//	import java.text.*;

public class helloworld{
	
	static boolean check (int a, int b, int x) {
		
		if (a*b<=x) return false;
		
		if (a/b>=x) return false;
		
		if (a%b!=0) return false;
		
		return true;
		
	}
	
	public static void main(String args[]) {
		
		int i,j,x;
		
		int sym = 0;
		
		Scanner scan = new Scanner(System.in);
		
		x = scan.nextInt();
		
		LABEL1:
		
		for(i = 1; i <= x; i++){
			
			for(j = 1; j < i; j++) {
				
				if (check(i,j,x)){	
					
					System.out.print(i);
					
					System.out.print(' ');
					
					System.out.println(j);
					
					sym=1;
					
					break LABEL1;
					
				}
			}
			
		}
		
		if(sym!=1)
			
			LABEL2:
			
			for(i = 1; i <= x; i++){
				
				for(j = 1; j <= i; j++) {
					
					if (check(i,j,x)){	
						
						System.out.print(i);
						
						System.out.print(' ');
						
						System.out.println(j);
						
						sym=1;
						
						break LABEL2;
						
					}
				}
				
			}
		
		if(sym!=1)  System.out.println(-1);
		
		scan.close();
		
		Runtime.getRuntime().exit(0);
			
	}
	
}