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