#include <iostream>
using namespace std;
void calculationResult(int A,int B)
{
    if (A<0 ||B<0)
    {
        cout<<"Invalid input";
        return;
    }
    if (A%2==0&&B%2==0)
    {
        cout<<A*B;
    }
    else if(A%2!=0&&B%2!=0)
    {
        cout<<A+B;
    }
    else
    {
        if(A>B)
            cout<<A-B;
        else
            cout<<B-A;
    }
}
int main()
{
    inr A,B;
    cin>>A;
    cin>>B;
    calculateResult(A,B);
    return 0;
}