#include<iostream>
using namespace std;

void calculateResult(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;
    calucateResult(A,B);
    
    return 0;
}