// editor1
#include <iostream>
using namespace std;
void calculateResult(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()
{
    int A,B;
    cin >> A;
    cin >> B;
    calculateResult(A,B);
    return 0;
}