#include<iostream>
using namespace std;
int main()
{
    int a,b;
    cin>>b>>b;
    if(a<0 ||b<0)
    {
        cout<<"Invalid input"<<endl;
    }
    else
    {
        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;
                }
            }
        }
    }   
    return 0;
}