// editor1
#include <iostream>
using namespace std;
int main()
{
    int a,b;
    cin>>a>>b;
    if (-100<=n<=100)
    {

    if (a<0 || b<0)
    {
        cout<<"Invalid input";
    }
    
    else if(a%2==0 && b%2==0)
    {
        cout<<a*b;
        
    }
    else if (a%2!=0 && b%2!=0)
    {
        cout<<a+b;
        
    }
    else 
    {
        cout<<a-b;
        
    }
    }
    
    return(0);
}