// editor1
#include<iostream>
using namespace std;
void calculateResult(int A,int B)
{
    if(A<0 ||B<0)
    {
        cout<<"Invalid input";
        return 0;
    }
    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;
}