import java.util.*;

public class Main {
  
 	public static void main(String[] args) {
     
      Scanner sc = new Scanner(System.in);
	  int n = Integer.parseInt(sc.next());
      int m = Integer.parseInt(sc.next());
      
      int max = m*n;
      
      if(max < m+n) {
        max = m+n;
      }
      
      if(max < n-m) {
        max = n-m;
      }
      
      System.out.println(max);
    }
  
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz