#include<bits/stdc++.h>
using namespace std;
int main(){
	double a,b,x,y,z;
	cin>>a>>b;
	x=a+b;
	y=a-b;
	z=a*b;
	if(a==0&&b==0)cout<<"0"<<endl;
	if(x>z&&x>y)cout<<x<<endl;
	if(y>z&&y>x)cout<<y<<endl;
	if(z>x&&z>y)cout<<z<<endl;
	return 0;
}