Language: C++

using namespace std;

int main(){
  int A,B,max1,max2,max3;
  cin >> A >> B;
  
  max1 = A + B;
  max2 = A - B;
  max3 = A * B;
  
  if (max1 < max2 && max2 < max3){
    cout << max3 << endl;
  }
  
  else if (max1 < max3 && max3 < max2){
    cout << max2 << endl;
  }
  
  else if (max2 < max3 && max3 < max1){
    cout << max1 << endl;
  }
  
  else if (max2 < max1 && max1 < max3){
    cout << max3 << endl;
  }
  
  else if (max3 < max1 && max1 < max2){
    cout << max2 << endl;
  }
  
  else if (max3 < max2 && max2 < max1){
    cout << max1 << endl;
  }
  
  else if (max1 == max2 && max1 > max3){
    cout << max1 << endl;
  }
  
  else if (max1 == max3 && max1 > max2){
    cout << max1 << endl;
  }
}

Compiler output:
a.cc: In function 'int main()':
a.cc:5:3: error: 'cin' was not declared in this scope
    5 |   cin >> A >> B;
      |   ^~~
a.cc:1:1: note: 'std::cin' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
  +++ |+#include <iostream>
    1 | using namespace std;
a.cc:12:5: error: 'cout' was not declared in this scope
   12 |     cout << max3 << endl;
      |     ^~~~
a.cc:12:5: note: 'std::cout' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
a.cc:12:21: error: 'endl' was not declared in this scope
   12 |     cout << max3 << endl;
      |                     ^~~~
a.cc:1:1: note: 'std::endl' is defined in header '<ostream>'; this is probably fixable by adding '#include <ostream>'
  +++ |+#include <ostream>
    1 | using namespace std;
a.cc:16:5: error: 'cout' was not declared in this scope
   16 |     cout << max2 << endl;
      |     ^~~~
a.cc:16:5: note: 'std::cout' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
a.cc:16:21: error: 'endl' was not declared in this scope
   16 |     cout << max2 << endl;
      |                     ^~~~
a.cc:16:21: note: 'std::endl' is defined in header '<ostream>'; this is probably fixable by adding '#include <ostream>'
a.cc:20:5: error: 'cout' was not declared in this scope
   20 |     cout << max1 << endl;
      |     ^~~~
a.cc:20:5: note: 'std::cout' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
a.cc:20:21: error: 'endl' was not declared in this scope
   20 |     cout << max1 << endl;
      |                     ^~~~
a.cc:20:21: note: 'std::endl' is defined in header '<ostream>'; this is probably fixable by adding '#include <ostream>'
a.cc:24:5: error: 'cout' was not declared in this scope
   24 |     cout << max3 << endl;
      |     ^~~~
a.cc:24:5: note: 'std::cout' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
a.cc:24:21: error: 'endl' was not declared in this scope
   24 |     cout << max3 << endl;
      |                     ^~~~
a.cc:24:21: note: 'std::endl' is defined in header '<ostream>'; this is probably fixable by adding '#include <ostream>'
a.cc:28:5: error: 'cout' was not declared in this scope
   28 |     cout << max2 << endl;
      |     ^~~~
a.cc:28:5: note: 'std::cout' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
a.cc:28:21: error: 'endl' was not declared in this scope
   28 |     cout << max2 << endl;
      |                     ^~~~
a.cc:28:21: note: 'std::endl' is defined in header '<ostream>'; this is probably fixable by adding '#include <ostream>'
a.cc:32:5: error: 'cout' was not declared in this scope
   32 |     cout << max1 << endl;
      |     ^~~~
a.cc:32:5: note: 'std::cout' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
a.cc:32:21: error: 'endl' was not declared in this scope
   32 |     cout << max1 << endl;
      |                     ^~~~
a.cc:32:21: note: 'std::endl' is defined in header '<ostream>'; this is probably fixable by adding '#include <ostream>'
a.cc:36:5: error: 'cout' was not declared in this scope
   36 |     cout << max1 << endl;
      |     ^~~~
a.cc:36:5: note: 'std::cout' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
a.cc:36:21: error: 'endl' was not declared in this scope
   36 |     cout << max1 << endl;
      |                     ^~~~
a.cc:36:21: note: 'std::endl' is defined in header '<ostream>'; this is probably fixable by adding '#include <ostream>'
a.cc:40:5: error: 'cout' was not declared in this scope
   40 |     cout << max1 << endl;
      |     ^~~~
a.cc:40:5: note: 'std::cout' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
a.cc:40:21: error: 'endl' was not declared in this scope
   40 |     cout << max1 << endl;
      |                     ^~~~
a.cc:40:21: note: 'std::endl' is defined in header '<ostream>'; this is probably fixable by adding '#include <ostream>'