Language: C++

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

int main(){
  cin >> A >> B >> C;
  
  vector<int> inputs;
  
  inputs.push_back(A);
  inputs.push_back(B);
  inputs.push_back(C);
  
  five = std::count(inputs.begin(),inputs.end(),5);
  seven = std::count(inputs.begin(),inputs.end(),7);
  
  if(five == 2 && seven == 1)cout << "YES";
  else cout << "NO";
}

Compiler output:
a.cc: In function 'int main()':
a.cc:6:3: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    6 |   cin >> A >> B >> C;
      |   ^~~
      |   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:6:10: error: 'A' was not declared in this scope
    6 |   cin >> A >> B >> C;
      |          ^
a.cc:6:15: error: 'B' was not declared in this scope
    6 |   cin >> A >> B >> C;
      |               ^
a.cc:6:20: error: 'C' was not declared in this scope
    6 |   cin >> A >> B >> C;
      |                    ^
a.cc:8:3: error: 'vector' was not declared in this scope
    8 |   vector<int> inputs;
      |   ^~~~~~
a.cc:8:3: note: suggested alternatives:
In file included from /usr/include/c++/14/vector:66,
                 from a.cc:3:
/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:8:10: error: expected primary-expression before 'int'
    8 |   vector<int> inputs;
      |          ^~~
a.cc:10:3: error: 'inputs' was not declared in this scope; did you mean 'puts'?
   10 |   inputs.push_back(A);
      |   ^~~~~~
      |   puts
a.cc:14:3: error: 'five' was not declared in this scope
   14 |   five = std::count(inputs.begin(),inputs.end(),5);
      |   ^~~~
a.cc:14:15: error: 'count' is not a member of 'std'; did you mean 'cout'?
   14 |   five = std::count(inputs.begin(),inputs.end(),5);
      |               ^~~~~
      |               cout
a.cc:15:3: error: 'seven' was not declared in this scope; did you mean 'setenv'?
   15 |   seven = std::count(inputs.begin(),inputs.end(),7);
      |   ^~~~~
      |   setenv
a.cc:15:16: error: 'count' is not a member of 'std'; did you mean 'cout'?
   15 |   seven = std::count(inputs.begin(),inputs.end(),7);
      |                ^~~~~
      |                cout
a.cc:17:30: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   17 |   if(five == 2 && seven == 1)cout << "YES";
      |                              ^~~~
      |                              std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:18:8: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   18 |   else cout << "NO";
      |        ^~~~
      |        std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~