Language: C++

#include <iostream>
#include <vector>
using namespacestd ;
int main ( ) {
int n,m;
cin >> n >> m;
vector<bool> vis ( n+1, false ) ;
bool ans = false ;
f o r ( int i = 0 ; i < m; i++) {
int a , b ;
cin >> a >> b ;
assert ( 1 <= a && a < b && b <= n ) ;
if ( a == 1 ) {
if ( vis [ b ] ) {
ans = true ;
}
vis [ b ] = true ;
} else if ( b == n ) {
if ( vis [ a ] ) {
ans = true ;
}
vis [ a ] = true ;
}
}
if ( ! ans ) cout << ”IM ” ;
cout << ”POSSIBLE” << endl ;
return 0 ;
}

Compiler output:
a.cc:25:22: error: extended character ” is not valid in an identifier
   25 | if ( ! ans ) cout << ”IM ” ;
      |                      ^
a.cc:25:26: error: extended character ” is not valid in an identifier
   25 | if ( ! ans ) cout << ”IM ” ;
      |                          ^
a.cc:26:9: error: extended character ” is not valid in an identifier
   26 | cout << ”POSSIBLE” << endl ;
      |         ^
a.cc:26:9: error: extended character ” is not valid in an identifier
a.cc:3:7: error: expected nested-name-specifier before 'namespacestd'
    3 | using namespacestd ;
      |       ^~~~~~~~~~~~
a.cc: In function 'int main()':
a.cc:6:1: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    6 | cin >> n >> m;
      | ^~~
      | std::cin
In file included from a.cc:1:
/usr/include/c++/14/iostream:62:18: note: 'std::cin' declared here
   62 |   extern istream cin;           ///< Linked to standard input
      |                  ^~~
a.cc:7:1: error: 'vector' was not declared in this scope
    7 | vector<bool> vis ( n+1, false ) ;
      | ^~~~~~
a.cc:7:1: note: suggested alternatives:
In file included from /usr/include/c++/14/vector:66,
                 from a.cc:2:
/usr/include/c++/14/bits/stl_vector.h:428:11: note:   'std::vector'
  428 |     class vector : protected _Vector_base<_Tp, _Alloc>
      |           ^~~~~~
/usr/include/c++/14/vector:93:13: note:   'std::pmr::vector'
   93 |       using vector = std::vector<_Tp, polymorphic_allocator<_Tp>>;
      |             ^~~~~~
a.cc:7:8: error: expected primary-expression before 'bool'
    7 | vector<bool> vis ( n+1, false ) ;
      |        ^~~~
a.cc:9:1: error: 'f' was not declared in this scope
    9 | f o r ( int i = 0 ; i < m; i++) {
      | ^
a.cc:9:21: error: 'i' was not declared in this scope
    9 | f o r ( int i = 0 ; i < m; i++) {
      |                     ^
a.cc:25:14: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   25 | if ( ! ans ) cout << ”IM ” ;
      |              ^~~~
      |              std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:25:22: error: '\U0000201dIM' was not declared in this scope
   25 | if ( ! ans ) cout << ”IM ” ;
      |                      ^~~
a.cc:26:1: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   26 | cout << ”POSSIBLE” << 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:26:9: error: '\U0000201dPOSSIBLE\U0000201d' was not declared in this scope
   26 | cout << ”POSSIBLE” << endl ;
      |         ^~~~~~~~~~
a.cc:26:23: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   26 | cout << ”POSSIBLE” << endl ;
      |                       ^~~~
      |                       std::endl
In file included from /usr/include/c++/14/iostream:41:
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~