/in/foo.cc: In function 'int main()':
/in/foo.cc:6:9: error: 'cin' was not declared in this scope
  while (cin.get(a))
         ^
/in/foo.cc:9:16: error: 'cout' was not declared in this scope
   if (a == '0')cout << '1';
                ^
/in/foo.cc:10:16: error: 'cout' was not declared in this scope
   if (a == '1')cout << '0';
                ^
/in/foo.cc:11:17: error: 'cout' was not declared in this scope
   if (a == '\n')cout << endl;
                 ^
/in/foo.cc:11:25: error: 'endl' was not declared in this scope
   if (a == '\n')cout << endl;
                         ^