/in/foo.cc: In function 'int main()':
/in/foo.cc:6:2: error: 'cin' was not declared in this scope
  cin>>x;
  ^~~
/in/foo.cc:6:2: note: suggested alternative: 'main'
  cin>>x;
  ^~~
  main
/in/foo.cc:10:2: error: 'cout' was not declared in this scope
  cout <<k;
  ^~~~