Pythagorean mathematics

Source: Cattle-off network

Given right-angled triangle in which the length of one side of n, is to construct your task remaining two sides, so that it can form three sides of a right triangle.
Input Description:
an integer n.
Output Description:
other two sides b, c. The answer is not unique, as long as any set of output that is reasonable, if you can not make construction output -1.
Example 1
Input

Copy
3
Output

Copy
45
Example 2
input

Copy
4
Output

Copy
35
Note:
0 <= n-<= 1E9

1<=b,c<=1e18

n, b, c are integers

#include <iostream>

using namespace std;

int main()
{
    long long n;

    cin >> n;

    if(n<=2)
        cout << "-1" << " " << "-1" << endl;

    if(n%2)
        cout<<(n*n+1)/2<<' '<<(n*n-1)/2<<endl;
    else
        cout<<(n*n+4)/4<<' '<<(n*n-4)/4<<endl;

    return 0;
}