import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Scanner;
class Main{


	static final int MOD = 1000000007;

	static	ArrayList<TreeNode> tree;
	static HashSet<Integer> set;
	static int[] ans;

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);			//文字の入力
		int a = sc.nextInt();
		int b = sc.nextInt();
		int[] data = {a+b,a-b,a*b};
		Arrays.sort(data);
		System.out.println(data[2]);
	}





	static int upperbond(int k,ArrayList<Integer> data){		//k以下で最大の値をdataの中から探し、返す二分探索
		if(data == null){
			return -1;
		}
		int max = data.size();
		int min = -1;
		while(max-min > 1){
			int mid = (max+min)/2;
			if(data.get(mid) <= k){
				min = mid;
			}else{
				max = mid;
			}
		}

		
//		if(min != -1){
//			min = data.get(min);
//		}
		
//		System.out.println(max);
		return min;					//indexを返している
	}

	static int lowerbond(int k,ArrayList<Integer> data){		//k以上で最小の値をdataの中から探し、返す二分探索
		if(data == null){
			return -1;
		}
//		System.out.println("lo");
//		System.out.println("lo");
		int max = data.size();
		int min = -1;

		while(max-min > 1){
			int mid = (max+min)/2;
			if(data.get(mid) >= k){
				max = mid;
			}else{
				min = mid;
			}
		}

		return max;			//indexを返している
	}



	static int gcd(int a,int b){				//最大公約数を返す
		if(b == 0){
			return a;
		}else{
			return gcd(b, a%b);
		}
	}
	static long gcd(long a,long b){
		if(b == 0){
			return a;
		}else{
			return gcd(b, a%b);
		}
	}



	static long lcm (long a, long b) {
		long g = gcd(a,b);
		return a/g*b;
	}




}

class TreeNode{
	int value;
	int sum;
	ArrayList<TreeNode> childlen;

	public TreeNode(int v,int s) {
		this.value = v;
		this.sum = s;
		this.childlen = new ArrayList<TreeNode>();
	}


}


class Edge  implements Comparable{

	int index;
	HashSet<Integer> hen;
	HashSet<Integer> used;
	HashMap<Integer, Integer> map;
	int size;


	public Edge(int index) {
		// TODO 自動生成されたコンストラクター・スタブ
		this.index = index;
		hen = new HashSet();
		used = new HashSet<Integer>();
		map = new HashMap<Integer,Integer>();
	}

	public int compareTo(Object other) {
		Edge otherpair = (Edge)other;

		return   otherpair.hen.size() - hen.size();
	}
}

class Pair implements Comparable{
	int from;
	int end;
	public Pair(int from,int end) {
		this.from = from;
		this.end = end;
		// TODO 自動生成されたコンストラクター・スタブ
	}

	@Override
	public int compareTo(Object other) {
		Pair otherpair = (Pair)other;

		return  from - otherpair.from;
	}








}



 import java.util.ArrayList; ArrayList java.util import java.util.Arrays; Arrays java.util import java.util.HashMap; HashMap java.util import java.util.HashSet; HashSet java.util import java.util.Scanner; Scanner java.util class Main{


	static final int MOD = 1000000007;

	static	ArrayList<TreeNode> tree;
	static HashSet<Integer> set;
	static int[] ans;

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);			//文字の入力
		int a = sc.nextInt();
		int b = sc.nextInt();
		int[] data = {a+b,a-b,a*b};
		Arrays.sort(data);
		System.out.println(data[2]);
	}





	static int upperbond(int k,ArrayList<Integer> data){		//k以下で最大の値をdataの中から探し、返す二分探索
		if(data == null){
			return -1;
		}
		int max = data.size();
		int min = -1;
		while(max-min > 1){
			int mid = (max+min)/2;
			if(data.get(mid) <= k){
				min = mid;
			}else{
				max = mid;
			}
		}

		
//		if(min != -1){
//			min = data.get(min);
//		}
		
//		System.out.println(max);
		return min;					//indexを返している
	}

	static int lowerbond(int k,ArrayList<Integer> data){		//k以上で最小の値をdataの中から探し、返す二分探索
		if(data == null){
			return -1;
		}
//		System.out.println("lo");
//		System.out.println("lo");
		int max = data.size();
		int min = -1;

		while(max-min > 1){
			int mid = (max+min)/2;
			if(data.get(mid) >= k){
				max = mid;
			}else{
				min = mid;
			}
		}

		return max;			//indexを返している
	}



	static int gcd(int a,int b){				//最大公約数を返す
		if(b == 0){
			return a;
		}else{
			return gcd(b, a%b);
		}
	}
	static long gcd(long a,long b){
		if(b == 0){
			return a;
		}else{
			return gcd(b, a%b);
		}
	}



	static long lcm (long a, long b) {
		long g = gcd(a,b);
		return a/g*b;
	}




} Main static final int MOD = 1000000007; MOD 1000000007 static	ArrayList<TreeNode> tree; tree static HashSet<Integer> set; set static int[] ans; ans public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);			//文字の入力
		int a = sc.nextInt();
		int b = sc.nextInt();
		int[] data = {a+b,a-b,a*b};
		Arrays.sort(data);
		System.out.println(data[2]);
	} main {
		Scanner sc = new Scanner(System.in);			//文字の入力
		int a = sc.nextInt();
		int b = sc.nextInt();
		int[] data = {a+b,a-b,a*b};
		Arrays.sort(data);
		System.out.println(data[2]);
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int a = sc.nextInt(); a sc.nextInt() sc.nextInt sc int b = sc.nextInt(); b sc.nextInt() sc.nextInt sc int[] data = {a+b,a-b,a*b}; data {a+b,a-b,a*b} a+b a b a-b a b a*b a b Arrays.sort(data) Arrays.sort Arrays data System.out.println(data[2]) System.out.println System.out System System.out data[2] data 2 String[] args args static int upperbond(int k,ArrayList<Integer> data){		//k以下で最大の値をdataの中から探し、返す二分探索
		if(data == null){
			return -1;
		}
		int max = data.size();
		int min = -1;
		while(max-min > 1){
			int mid = (max+min)/2;
			if(data.get(mid) <= k){
				min = mid;
			}else{
				max = mid;
			}
		}

		
//		if(min != -1){
//			min = data.get(min);
//		}
		
//		System.out.println(max);
		return min;					//indexを返している
	} upperbond {		//k以下で最大の値をdataの中から探し、返す二分探索
		if(data == null){
			return -1;
		}
		int max = data.size();
		int min = -1;
		while(max-min > 1){
			int mid = (max+min)/2;
			if(data.get(mid) <= k){
				min = mid;
			}else{
				max = mid;
			}
		}

		
//		if(min != -1){
//			min = data.get(min);
//		}
		
//		System.out.println(max);
		return min;					//indexを返している
	} if(data == null){
			return -1;
		} data == null data null {
			return -1;
		} return -1; -1 1 int max = data.size(); max data.size() data.size data int min = -1; min -1 1 while(max-min > 1){
			int mid = (max+min)/2;
			if(data.get(mid) <= k){
				min = mid;
			}else{
				max = mid;
			}
		} max-min > 1 max-min max min 1 {
			int mid = (max+min)/2;
			if(data.get(mid) <= k){
				min = mid;
			}else{
				max = mid;
			}
		} int mid = (max+min)/2; mid (max+min)/2 (max+min) max min 2 if(data.get(mid) <= k){
				min = mid;
			}else{
				max = mid;
			} data.get(mid) <= k data.get(mid) data.get data mid k {
				min = mid;
			} min = mid min mid {
				max = mid;
			} max = mid max mid return min;					//indexを返している min int k k ArrayList<Integer> data data static int lowerbond(int k,ArrayList<Integer> data){		//k以上で最小の値をdataの中から探し、返す二分探索
		if(data == null){
			return -1;
		}
//		System.out.println("lo");
//		System.out.println("lo");
		int max = data.size();
		int min = -1;

		while(max-min > 1){
			int mid = (max+min)/2;
			if(data.get(mid) >= k){
				max = mid;
			}else{
				min = mid;
			}
		}

		return max;			//indexを返している
	} lowerbond {		//k以上で最小の値をdataの中から探し、返す二分探索
		if(data == null){
			return -1;
		}
//		System.out.println("lo");
//		System.out.println("lo");
		int max = data.size();
		int min = -1;

		while(max-min > 1){
			int mid = (max+min)/2;
			if(data.get(mid) >= k){
				max = mid;
			}else{
				min = mid;
			}
		}

		return max;			//indexを返している
	} if(data == null){
			return -1;
		} data == null data null {
			return -1;
		} return -1; -1 1 int max = data.size(); max data.size() data.size data int min = -1; min -1 1 while(max-min > 1){
			int mid = (max+min)/2;
			if(data.get(mid) >= k){
				max = mid;
			}else{
				min = mid;
			}
		} max-min > 1 max-min max min 1 {
			int mid = (max+min)/2;
			if(data.get(mid) >= k){
				max = mid;
			}else{
				min = mid;
			}
		} int mid = (max+min)/2; mid (max+min)/2 (max+min) max min 2 if(data.get(mid) >= k){
				max = mid;
			}else{
				min = mid;
			} data.get(mid) >= k data.get(mid) data.get data mid k {
				max = mid;
			} max = mid max mid {
				min = mid;
			} min = mid min mid return max;			//indexを返している max int k k ArrayList<Integer> data data static int gcd(int a,int b){				//最大公約数を返す
		if(b == 0){
			return a;
		}else{
			return gcd(b, a%b);
		}
	} gcd {				//最大公約数を返す
		if(b == 0){
			return a;
		}else{
			return gcd(b, a%b);
		}
	} if(b == 0){
			return a;
		}else{
			return gcd(b, a%b);
		} b == 0 b 0 {
			return a;
		} return a; a {
			return gcd(b, a%b);
		} return gcd(b, a%b); gcd(b, a%b) gcd b a%b a b int a a int b b static long gcd(long a,long b){
		if(b == 0){
			return a;
		}else{
			return gcd(b, a%b);
		}
	} gcd {
		if(b == 0){
			return a;
		}else{
			return gcd(b, a%b);
		}
	} if(b == 0){
			return a;
		}else{
			return gcd(b, a%b);
		} b == 0 b 0 {
			return a;
		} return a; a {
			return gcd(b, a%b);
		} return gcd(b, a%b); gcd(b, a%b) gcd b a%b a b long a a long b b static long lcm (long a, long b) {
		long g = gcd(a,b);
		return a/g*b;
	} lcm {
		long g = gcd(a,b);
		return a/g*b;
	} long g = gcd(a,b); g gcd(a,b) gcd a b return a/g*b; a/g*b a/g a g b long a a long b b class TreeNode{
	int value;
	int sum;
	ArrayList<TreeNode> childlen;

	public TreeNode(int v,int s) {
		this.value = v;
		this.sum = s;
		this.childlen = new ArrayList<TreeNode>();
	}


} TreeNode int value; value int sum; sum ArrayList<TreeNode> childlen; childlen public TreeNode(int v,int s) {
		this.value = v;
		this.sum = s;
		this.childlen = new ArrayList<TreeNode>();
	} TreeNode {
		this.value = v;
		this.sum = s;
		this.childlen = new ArrayList<TreeNode>();
	} this.value = v this.value this this.value v this.sum = s this.sum this this.sum s this.childlen = new ArrayList<TreeNode>() this.childlen this this.childlen new ArrayList<TreeNode>() int v v int s s class Edge  implements Comparable{

	int index;
	HashSet<Integer> hen;
	HashSet<Integer> used;
	HashMap<Integer, Integer> map;
	int size;


	public Edge(int index) {
		// TODO 自動生成されたコンストラクター・スタブ
		this.index = index;
		hen = new HashSet();
		used = new HashSet<Integer>();
		map = new HashMap<Integer,Integer>();
	}

	public int compareTo(Object other) {
		Edge otherpair = (Edge)other;

		return   otherpair.hen.size() - hen.size();
	}
} Edge int index; index HashSet<Integer> hen; hen HashSet<Integer> used; used HashMap<Integer, Integer> map; map int size; size public Edge(int index) {
		// TODO 自動生成されたコンストラクター・スタブ
		this.index = index;
		hen = new HashSet();
		used = new HashSet<Integer>();
		map = new HashMap<Integer,Integer>();
	} Edge {
		// TODO 自動生成されたコンストラクター・スタブ
		this.index = index;
		hen = new HashSet();
		used = new HashSet<Integer>();
		map = new HashMap<Integer,Integer>();
	} this.index = index this.index this this.index index hen = new HashSet() hen new HashSet() used = new HashSet<Integer>() used new HashSet<Integer>() map = new HashMap<Integer,Integer>() map new HashMap<Integer,Integer>() int index index public int compareTo(Object other) {
		Edge otherpair = (Edge)other;

		return   otherpair.hen.size() - hen.size();
	} compareTo {
		Edge otherpair = (Edge)other;

		return   otherpair.hen.size() - hen.size();
	} Edge otherpair = (Edge)other; otherpair (Edge)other return   otherpair.hen.size() - hen.size(); otherpair.hen.size() - hen.size() otherpair.hen.size() otherpair.hen.size otherpair.hen otherpair otherpair.hen hen.size() hen.size hen Object other other Comparable class Pair implements Comparable{
	int from;
	int end;
	public Pair(int from,int end) {
		this.from = from;
		this.end = end;
		// TODO 自動生成されたコンストラクター・スタブ
	}

	@Override
	public int compareTo(Object other) {
		Pair otherpair = (Pair)other;

		return  from - otherpair.from;
	}








} Pair int from; from int end; end public Pair(int from,int end) {
		this.from = from;
		this.end = end;
		// TODO 自動生成されたコンストラクター・スタブ
	} Pair {
		this.from = from;
		this.end = end;
		// TODO 自動生成されたコンストラクター・スタブ
	} this.from = from this.from this this.from from this.end = end this.end this this.end end int from from int end end @Override
	public int compareTo(Object other) {
		Pair otherpair = (Pair)other;

		return  from - otherpair.from;
	} compareTo {
		Pair otherpair = (Pair)other;

		return  from - otherpair.from;
	} Pair otherpair = (Pair)other; otherpair (Pair)other return  from - otherpair.from; from - otherpair.from from otherpair.from otherpair otherpair.from Object other other Comparable
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Scanner;
class Main{


	static final int MOD = 1000000007;

	static	ArrayList<TreeNode> tree;
	static HashSet<Integer> set;
	static int[] ans;

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);			//文字の入力
		int a = sc.nextInt();
		int b = sc.nextInt();
		int[] data = {a+b,a-b,a*b};
		Arrays.sort(data);
		System.out.println(data[2]);
	}





	static int upperbond(int k,ArrayList<Integer> data){		//k以下で最大の値をdataの中から探し、返す二分探索
		if(data == null){
			return -1;
		}
		int max = data.size();
		int min = -1;
		while(max-min > 1){
			int mid = (max+min)/2;
			if(data.get(mid) <= k){
				min = mid;
			}else{
				max = mid;
			}
		}

		
//		if(min != -1){
//			min = data.get(min);
//		}
		
//		System.out.println(max);
		return min;					//indexを返している
	}

	static int lowerbond(int k,ArrayList<Integer> data){		//k以上で最小の値をdataの中から探し、返す二分探索
		if(data == null){
			return -1;
		}
//		System.out.println("lo");
//		System.out.println("lo");
		int max = data.size();
		int min = -1;

		while(max-min > 1){
			int mid = (max+min)/2;
			if(data.get(mid) >= k){
				max = mid;
			}else{
				min = mid;
			}
		}

		return max;			//indexを返している
	}



	static int gcd(int a,int b){				//最大公約数を返す
		if(b == 0){
			return a;
		}else{
			return gcd(b, a%b);
		}
	}
	static long gcd(long a,long b){
		if(b == 0){
			return a;
		}else{
			return gcd(b, a%b);
		}
	}



	static long lcm (long a, long b) {
		long g = gcd(a,b);
		return a/g*b;
	}




}

class TreeNode{
	int value;
	int sum;
	ArrayList<TreeNode> childlen;

	public TreeNode(int v,int s) {
		this.value = v;
		this.sum = s;
		this.childlen = new ArrayList<TreeNode>();
	}


}


class Edge  implements Comparable{

	int index;
	HashSet<Integer> hen;
	HashSet<Integer> used;
	HashMap<Integer, Integer> map;
	int size;


	public Edge(int index) {
		// TODO 自動生成されたコンストラクター・スタブ
		this.index = index;
		hen = new HashSet();
		used = new HashSet<Integer>();
		map = new HashMap<Integer,Integer>();
	}

	public int compareTo(Object other) {
		Edge otherpair = (Edge)other;

		return   otherpair.hen.size() - hen.size();
	}
}

class Pair implements Comparable{
	int from;
	int end;
	public Pair(int from,int end) {
		this.from = from;
		this.end = end;
		// TODO 自動生成されたコンストラクター・スタブ
	}

	@Override
	public int compareTo(Object other) {
		Pair otherpair = (Pair)other;

		return  from - otherpair.from;
	}








}




