#include<iostream>
using namespace std;
int main()
{
    int A, B;
    if(!(cin>>A>>B))
    {
        return 0;
    }
    if (A < 0 || B < 0)
    {
        cout << "Invalid input" << endl;
    }
    else if(A % 2 == 0 && B % 2 == 0)
    {
        cout << A * B <<endl;
    }
    else if (A % 2 != 0 && B % 2 != 0)
    {
        cout << A + B << endl;
    }
    else 
    {
        if(A>B) cout << A - B << endl;
        else cout<<B-A<<;
    }
    return 0;
}