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;
int read() {
  int x = 0, f = 1;
  char ch = getchar();
  while (ch < '0' || ch > '9') {
    if (ch == '-') f = -1;
    ch = getchar();
  }
  while (ch >= '0' && ch <= '9') {
    x = 10 * x + ch - '0';
    ch = getchar();
  }
  return x * f;
}
int gcd(int x, int y) { return y ? gcd(y, x % y) : x; }
int power(int x, int y) {
  int t = 1;
  for (; y; y >>= 1, x = x * x % 1000000007)
    if (y & 1) t = t * x % 1000000007;
  return t;
}
int n;
int main() {
  n = read();
  int a, b;
  for (a = 1; a <= n; a++)
    for (b = 1; b <= n; b++)
      if (a % b == 0) {
        if (a * b > n && a < n * b) {
          cout << a << " " << b << endl;
          return 0;
        }
      }
  cout << -1 << endl;
  return 0;
}