#!/usr/bin/env python
# -*- coding: utf-8 -*-

def memoize(f):
    cache = {}
    def helper(*args):
        if args not in cache:
            cache[args] = f(*args)
        return cache[args]
    return helper

import sys
from operator import itemgetter
n = int(sys.stdin.readline().split(' ')[0])

@memoize
def s2(n):
    if n <= 1:
        if n == 1: return True
        else: return False
    else: return s2(n / 2.)

can = []
for i in xrange(n-1):
    can.append((i+1, n-(i+1)))

can = filter(lambda ((x, y)): not s2(x) and not s2(y), can)
can = sorted(can, key=itemgetter(0))
if len(can) == 0:
    print("-1")
else:
    print("%d %d" % (can[0][0], can[0][1]))