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 CPP):

Solution:
#include <bits/stdc++.h>
using namespace std;
long long INF = 1 << 28;
const double pi = acos(-1.0);
int fx[] = {1, -1, 0, 0};
int fy[] = {0, 0, 1, -1};
int dir[4][2] = {1, 0, -1, 0, 0, -1, 0, 1};
const long double EPS = 1e-7;
long long gcd(long long a, long long b) {
  if (b == 0)
    return a;
  else
    return gcd(b, a % b);
}
long long lcm(long long a, long long b) { return a / gcd(a, b) * b; }
bool cmp(int a, int b) { return a < b; }
struct compare {
  bool operator()(const int& l, const int& r) { return l > r; }
};
bool cmp1(int a, int b) { return a > b; }
struct Point {
  int x, y;
};
int main() {
  int x;
  scanf("%d", &x);
  if (x == 1)
    cout << -1 << endl;
  else
    cout << x << " " << x << endl;
  return 0;
}