Language: C++

                                                                                            
#include <iostream>                                                                                                                                                                                                                      
                                                                                                                                         
int main() {                                                                                                                             
                                                                                                                                         
  string s;                                                                                                                              
  cin >> s;                                                                                                                              
                                                                                                                                         
  int cnt = 0;                                                                                                                           
  char pre = 0x0;                                                                                                                        
                                                                                                                                         
  pre = s[0];                                                                                                                            
  if (pre == 'R') cnt++;                                                                                                                 
  for (int i = 1; i < 3; i++) {                                                                                                          
    if (s[i] == pre && pre == 'R') cnt++;                                                                                                
    pre = s[i];                                                                                                                          
  }                                                                                                                                      
                                                                                                                                         
  cout << cnt << endl;                                                                                                                   
                                                                                                                                         
  return 0;                                                                                                                              
                                                                                                                                         
}                                                                                                                                        
                         

Compiler output:
a.cc: In function 'int main()':
a.cc:6:3: error: 'string' was not declared in this scope
    6 |   string s;
      |   ^~~~~~
a.cc:6:3: 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:2:
/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:7:3: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    7 |   cin >> s;
      |   ^~~
      |   std::cin
/usr/include/c++/14/iostream:62:18: note: 'std::cin' declared here
   62 |   extern istream cin;           ///< Linked to standard input
      |                  ^~~
a.cc:7:10: error: 's' was not declared in this scope
    7 |   cin >> s;
      |          ^
a.cc:19:3: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   19 |   cout << cnt << 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:19:18: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   19 |   cout << cnt << endl;
      |                  ^~~~
      |                  std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~