#include<iostream>
#include<cmath>
using namespace std;
int mmax(int a,int b,int c){
	return max(a,max(b,c));
}
int main(){
	int m,n;
	while(cin>>m>>n){
		cout<<mmax(m-n,m+n,m*n)<<endl;
	}
	return 0;
}