Language: C++

#include <iostream>
#include <string>
#include <vector>
#include <sstream>

int main(void){

	string ts, a, b, outstr;
	getline(cin, ts);

	a = ts.substr(0, ts.find(' '));
	b = ts.substr(ts.find(' ') + 1, ts.size());

	int ia, ib;
	ia = stoi(a);
	ib = stoi(b);

	if (ia < ib)
	{
		outstr = "a < b";
	}
	else
	if (ia > ib)
	{
		outstr = "a > b";
	}
	else
	{
		outstr = "a == b";
	}

	cout << outstr << endl;

	return 0;

Compiler output:
a.cc: In function 'int main()':
a.cc:8:9: error: 'string' was not declared in this scope
    8 |         string ts, a, b, outstr;
      |         ^~~~~~
a.cc:8:9: note: suggested alternatives:
In file included from /usr/include/c++/14/iosfwd:41,
                 from /usr/include/c++/14/ios:40,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:1:
/usr/include/c++/14/bits/stringfwd.h:77:33: note:   'std::string'
   77 |   typedef basic_string<char>    string;
      |                                 ^~~~~~
In file included 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:
/usr/include/c++/14/string:76:11: note:   'std::pmr::string'
   76 |     using string    = basic_string<char>;
      |           ^~~~~~
a.cc:9:17: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    9 |         getline(cin, ts);
      |                 ^~~
      |                 std::cin
/usr/include/c++/14/iostream:62:18: note: 'std::cin' declared here
   62 |   extern istream cin;           ///< Linked to standard input
      |                  ^~~
a.cc:9:22: error: 'ts' was not declared in this scope; did you mean 'tm'?
    9 |         getline(cin, ts);
      |                      ^~
      |                      tm
a.cc:11:9: error: 'a' was not declared in this scope
   11 |         a = ts.substr(0, ts.find(' '));
      |         ^
a.cc:12:9: error: 'b' was not declared in this scope
   12 |         b = ts.substr(ts.find(' ') + 1, ts.size());
      |         ^
a.cc:15:14: error: 'stoi' was not declared in this scope; did you mean 'std::__cxx11::stoi'?
   15 |         ia = stoi(a);
      |              ^~~~
      |              std::__cxx11::stoi
In file included from /usr/include/c++/14/string:54:
/usr/include/c++/14/bits/basic_string.h:4432:3: note: 'std::__cxx11::stoi' declared here
 4432 |   stoi(const wstring& __str, size_t* __idx = 0, int __base = 10)
      |   ^~~~
a.cc:20:17: error: 'outstr' was not declared in this scope
   20 |                 outstr = "a < b";
      |                 ^~~~~~
a.cc:25:17: error: 'outstr' was not declared in this scope
   25 |                 outstr = "a > b";
      |                 ^~~~~~
a.cc:29:17: error: 'outstr' was not declared in this scope
   29 |                 outstr = "a == b";
      |                 ^~~~~~
a.cc:32:9: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   32 |         cout << outstr << endl;
      |         ^~~~
      |         std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:32:17: error: 'outstr' was not declared in this scope
   32 |         cout << outstr << endl;
      |                 ^~~~~~
a.cc:32:27: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   32 |         cout << outstr << endl;
      |                           ^~~~
      |                           std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
a.cc:34:18: error: expected '}' at end of input
   34 |         return 0;
      |                  ^
a.cc:6:15: note: to match this '{'
    6 | int main(void){
      |               ^