Language: C++

#include<iostream>
using namespace std;
int main()
{     
      int a,b;
      cin>>a>>b;
      while(a!="H"||a!="D"||b!="H"||b!="D")
      {
           cin>>a>>" ">>b;
      }
      if(a=="H") 
      {
          cout<<b;
      }
      if(a=="D")
      {
            if(b=="H")
            {  cout<< a; }
             else
            {cout<<"H";} 
 
       }
       return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:7:14: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
    7 |       while(a!="H"||a!="D"||b!="H"||b!="D")
      |             ~^~~~~
a.cc:7:22: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
    7 |       while(a!="H"||a!="D"||b!="H"||b!="D")
      |                     ~^~~~~
a.cc:7:30: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
    7 |       while(a!="H"||a!="D"||b!="H"||b!="D")
      |                             ~^~~~~
a.cc:7:38: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
    7 |       while(a!="H"||a!="D"||b!="H"||b!="D")
      |                                     ~^~~~~
a.cc:9:18: error: no match for 'operator>>' (operand types are 'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} and 'const char [2]')
    9 |            cin>>a>>" ">>b;
      |            ~~~~~~^~~~~
      |               |    |
      |               |    const char [2]
      |               std::basic_istream<char>::__istream_type {aka std::basic_istream<char>}
In file included from /usr/include/c++/14/iostream:42,
                 from a.cc:1:
/usr/include/c++/14/istream:170:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(bool&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  170 |       operator>>(bool& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:170:7: note:   conversion of argument 1 would be ill-formed:
a.cc:9:20: error: cannot bind non-const lvalue reference of type 'bool&' to a value of type 'const char*'
    9 |            cin>>a>>" ">>b;
      |                    ^~~
/usr/include/c++/14/istream:174:7: note: candidate: 'std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(short int&) [with _CharT = char; _Traits = std::char_traits<char>]' (near match)
  174 |       operator>>(short& __n);
      |       ^~~~~~~~
/usr/include/c++/14/istream:174:7: note:   conversion of argument 1 would be ill-formed:
a.cc:9:20: error: invalid conversion from 'const char*' to 'short int' [-fpermissive]
    9 |            cin>>a>>" ">>b;
      |                    ^~~
      |                    |
      |                    const char*
a.cc:9:20: error: cannot bind rvalue '(short int)((const char*)" ")' to 'short int&'
/usr/include/c++/14/istream:177:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(short unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  177 |       operator>>(unsigned short& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:177:7: note:   conversion of argument 1 would be ill-formed:
a.cc:9:20: error: invalid conversion from 'const char*' to 'short unsigned int' [-fpermissive]
    9 |            cin>>a>>" ">>b;
      |                    ^~~
      |                    |
      |                    const char*
a.cc:9:20: error: cannot bind rvalue '(short unsigned int)((const char*)" ")' to 'short unsigned int&'
/usr/include/c++/14/istream:181:7: note: candidate: 'std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(int&) [with _CharT = char; _Traits = std::char_traits<char>]' (near match)
  181 |       operator>>(int& __n);
      |       ^~~~~~~~
/usr/include/c++/14/istream:181:7: note:   conversion of argument 1 would be ill-formed:
a.cc:9:20: error: invalid conversion from 'const char*' to 'int' [-fpermissive]
    9 |            cin>>a>>" ">>b;
      |                    ^~~
      |                    |
      |                    const char*
a.cc:9:20: error: cannot bind rvalue '(int)((const char*)" ")' to 'int&'
/usr/include/c++/14/istream:184:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  184 |       operator>>(unsigned int& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:184:7: note:   conversion of argument 1 would be ill-formed:
a.cc:9:20: error: invalid conversion from 'const char*' to 'unsigned int' [-fpermissive]
    9 |            cin>>a>>" ">>b;
      |                    ^~~
      |                    |
      |                    const char*
a.cc:9:20: error: cannot bind rvalue '(unsigned int)((const char*)" ")' to 'unsigned int&'
/usr/include/c++/14/istream:188:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  188 |       operator>>(long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:188:7: note:   conversion of argument 1 would be ill-formed:
a.cc:9:20: error: invalid conversion from 'const char*' to 'long int' [-fpermissive]
    9 |            cin>>a>>" ">>b;
      |                    ^~~
      |                    |
      |                    const char*
a.cc:9:20: error: cannot bind rvalue '(long int)((const char*)" ")' to 'long int&'
/usr/include/c++/14/istream:192:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  192 |       operator>>(unsigned long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:192:7: note:   conversion of argument 1 would be ill-formed:
a.cc:9:20: error: invalid conversion from 'const char*' to 'long unsigned int' [-fpermissive]
    9 |            cin>>a>>" ">>b;
      |                    ^~~
      |                    |
      |                    const char*
a.cc:9:20: error: cannot bind rvalue '(long unsigned int)((const char*)" ")' to 'long unsigned int&'
/usr/include/c++/14/istream:199:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  199 |       operator>>(long long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:199:7: note:   conversion of argument 1 would be ill-formed:
a.cc:9:20: error: invalid conversion from 'const char*' to 'long long int' [-fpermissive]
    9 |            cin>>a>>" ">>b;
      |                    ^~~
      |                    |
      |                    const char*
a.cc:9:20: error: cannot bind rvalue '(long long int)((const char*)" ")' to 'long long int&'
/usr/include/c++/14/istream:203:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  203 |       operator>>(unsigned long long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:203:7: note:   conversion of argument 1 would be ill-formed:
a.cc:9:20: error: invalid conversion from 'const char*' to 'long long unsigned int' [-fpermissive]
    9 |            cin>>a>>" ">>b;
      |                    ^~~
      |                    |
      |                    const char*
a.cc:9:20: error: cannot bind rvalue '(long long unsigned int)((const char*)" ")' to 'long long unsigned int&'
/usr/include/c++/14/istream:328:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(void*&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  328 |       operator>>(void*& __p)
      |       ^~~~~~~~
/usr/include/c++/14/istream:328:7: note:   conversion of argument 1 would be ill-formed:
a.cc:9:20: error: invalid conversion from 'const void*' to 'void*' [-fpermissive]
    9 |            cin>>a>>" ">>b;
      |                    ^~~
      |                    |
      |                    const void*
a.cc:9:20: error: cannot bind rvalue '(void*)((const void*)((const char*)" "))' to 'void*&'
/usr/include/c++/14/istream:219:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(float&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]'
  219 |       operator>>(float& __f)
      |       ^~~~~~~~
/usr/include/c++/14/istream:219:25: note:   no known conversion for argument 1 from 'const char [2]' to 'float&'
  219 |       operator>>(float& __f)
      |                  ~~~~~~~^~~
/usr/include/c++/14/istream:223:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(double&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]'
  223 |       operator>>(double& __f)
      |       ^~~~~~~~
/usr/include/c++/14/istream:223:26: note:   no known conversion for argument 1 from 'const char [2]' to 'double&'
  223 |       operator>>(double& __f)
      |                  ~~~~~~~~^~~
/usr/include/c++/14/istream:227:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long double&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]'
  227 |       operator>>(long double& __f)
      |       ^~~~~~~~
/usr/include/c++/14/istream:227:31: note:   no known conversion for argument 1 from 'const char [2]' to 'long double&'
  227 |       operator>>(long double& __f)
      |                  ~~~~~~~~~~~~~^~~
/usr/include/c++/14/istream:122:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(__istream_type& (*)(__istream_type&)) [with _CharT = char; _Traits = std::char_trait