Language: C++

#import<iostream>
main(){char a,b;std::cin>>a>>b;std::cout<<'H'^a^b;}

Compiler output:
a.cc:1:2: warning: #import is a deprecated GCC extension [-Wdeprecated]
    1 | #import<iostream>
      |  ^~~~~~
a.cc:2:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
    2 | main(){char a,b;std::cin>>a>>b;std::cout<<'H'^a^b;}
      | ^~~~
a.cc: In function 'int main()':
a.cc:2:46: error: no match for 'operator^' (operand types are 'std::basic_ostream<char>' and 'char')
    2 | main(){char a,b;std::cin>>a>>b;std::cout<<'H'^a^b;}
      |                                ~~~~~~~~~~~~~~^~
      |                                         |     |
      |                                         |     char
      |                                         std::basic_ostream<char>
a.cc:2:46: note: candidate: 'operator^(int, int)' (built-in)
    2 | main(){char a,b;std::cin>>a>>b;std::cout<<'H'^a^b;}
      |                                ~~~~~~~~~~~~~~^~
a.cc:2:46: note:   no known conversion for argument 1 from 'std::basic_ostream<char>' to 'int'
In file included from /usr/include/c++/14/bits/memory_resource.h:38,
                 from /usr/include/c++/14/string:68,
                 from /usr/include/c++/14/bits/locale_classes.h:40,
                 from /usr/include/c++/14/bits/ios_base.h:41,
                 from /usr/include/c++/14/ios:44,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:1:
/usr/include/c++/14/cstddef:146:3: note: candidate: 'constexpr std::byte std::operator^(byte, byte)'
  146 |   operator^(byte __l, byte __r) noexcept
      |   ^~~~~~~~
/usr/include/c++/14/cstddef:146:18: note:   no known conversion for argument 1 from 'std::basic_ostream<char>' to 'std::byte'
  146 |   operator^(byte __l, byte __r) noexcept
      |             ~~~~~^~~
/usr/include/c++/14/bits/ios_base.h:94:3: note: candidate: 'constexpr std::_Ios_Fmtflags std::operator^(_Ios_Fmtflags, _Ios_Fmtflags)'
   94 |   operator^(_Ios_Fmtflags __a, _Ios_Fmtflags __b) _GLIBCXX_NOTHROW
      |   ^~~~~~~~
/usr/include/c++/14/bits/ios_base.h:94:27: note:   no known conversion for argument 1 from 'std::basic_ostream<char>' to 'std::_Ios_Fmtflags'
   94 |   operator^(_Ios_Fmtflags __a, _Ios_Fmtflags __b) _GLIBCXX_NOTHROW
      |             ~~~~~~~~~~~~~~^~~
/usr/include/c++/14/bits/ios_base.h:144:3: note: candidate: 'constexpr std::_Ios_Openmode std::operator^(_Ios_Openmode, _Ios_Openmode)'
  144 |   operator^(_Ios_Openmode __a, _Ios_Openmode __b) _GLIBCXX_NOTHROW
      |   ^~~~~~~~
/usr/include/c++/14/bits/ios_base.h:144:27: note:   no known conversion for argument 1 from 'std::basic_ostream<char>' to 'std::_Ios_Openmode'
  144 |   operator^(_Ios_Openmode __a, _Ios_Openmode __b) _GLIBCXX_NOTHROW
      |             ~~~~~~~~~~~~~~^~~
/usr/include/c++/14/bits/ios_base.h:191:3: note: candidate: 'constexpr std::_Ios_Iostate std::operator^(_Ios_Iostate, _Ios_Iostate)'
  191 |   operator^(_Ios_Iostate __a, _Ios_Iostate __b) _GLIBCXX_NOTHROW
      |   ^~~~~~~~
/usr/include/c++/14/bits/ios_base.h:191:26: note:   no known conversion for argument 1 from 'std::basic_ostream<char>' to 'std::_Ios_Iostate'
  191 |   operator^(_Ios_Iostate __a, _Ios_Iostate __b) _GLIBCXX_NOTHROW
      |             ~~~~~~~~~~~~~^~~