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 PYTHON3):

Solution:
##n = int(input())
##dta1,dta2 = [],[]
##for i in range(n):
##    a = input().split()
##    dta1.append(a[0])
##    dta2.append(a[1])
##
##data = ""
##for a in range(n):
##    for z in range(int(dta2[a])):
##        data += dta1[a]
##
##res = 0
##for i in data:
##    if(data.count(i) > res):
##        res = data.count(i)
##print(res)

x=int(input())
ex=False
for a in range(1,x+1):
    for b in range(1,x+1):
        if(a%b==0 and a*b>x and a/b<x):
            print(a,b)
            ex=True
            break
    if(ex):break
else:
    print(-1)