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 PYTHON):

Solution:
x=input()
flag=0
for b in range (1,x+1):
    k=x/(float(b**2))
    if k%1==0:
        k=int(k)
    else:
        k=int(k)+1
    while k<x:
        if b*k>=1 and b*k<=x and ((b**2)*k)>x:
            print b*k,b
            flag=1
            break
        k+=1
    if flag==1:
        break
if flag==0:
    print -1