#include <stdio.h>
#include <map>
#include <set>
#include <ctime>
#include <cmath>
#include <queue>
#include <stack>
#include <vector>
#include <string>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <functional>
using namespace std;
int main()
{
	long long a,b;
	scanf("%lld%lld",&a,&b);
	long long jia,jian,cheng;
	cheng=a*b;
	jia=a+b;
	jian=a-b;
	
	if ( jia>=jian && jia >=cheng  )
	printf("%lld\n",jia);
	else if(jian>=jia&&jian>=cheng)
	printf("%lld\n",jian);
	else if( cheng>=jia&&cheng>=jian )
	printf("%lld\n",cheng);
}