foo.cc: In function ‘int main()’:
foo.cc:6:9: error: expected initializer before ‘cin’
    6 |         cin>>a>>b>>c;
      |         ^~~
foo.cc:9:25: error: ‘cout’ was not declared in this scope
    9 |                         cout<<a<<"<"<<b<<"<"<<c<endl;   //123
      |                         ^~~~
foo.cc:1:1: note: ‘std::cout’ is defined in header ‘<iostream>’; did you forget to ‘#include <iostream>’?
  +++ |+#include <iostream>
    1 | using namespace std;
foo.cc:9:49: error: ‘endl’ was not declared in this scope
    9 |                         cout<<a<<"<"<<b<<"<"<<c<endl;   //123
      |                                                 ^~~~
foo.cc:1:1: note: ‘std::endl’ is defined in header ‘<ostream>’; did you forget to ‘#include <ostream>’?
  +++ |+#include <ostream>
    1 | using namespace std;
foo.cc:13:33: error: ‘cout’ was not declared in this scope
   13 |                                 cout<<a<<"<"<<c<<"<"<<b<<endl;//132
      |                                 ^~~~
foo.cc:13:33: note: ‘std::cout’ is defined in header ‘<iostream>’; did you forget to ‘#include <iostream>’?
foo.cc:13:58: error: ‘endl’ was not declared in this scope
   13 |                                 cout<<a<<"<"<<c<<"<"<<b<<endl;//132
      |                                                          ^~~~
foo.cc:13:58: note: ‘std::endl’ is defined in header ‘<ostream>’; did you forget to ‘#include <ostream>’?
foo.cc:15:33: error: ‘cout’ was not declared in this scope
   15 |                                 cout<<C<<"<"<<a<<"<"<<B<<endl;//231
      |                                 ^~~~
foo.cc:15:33: note: ‘std::cout’ is defined in header ‘<iostream>’; did you forget to ‘#include <iostream>’?
foo.cc:15:39: error: ‘C’ was not declared in this scope
   15 |                                 cout<<C<<"<"<<a<<"<"<<B<<endl;//231
      |                                       ^
foo.cc:15:55: error: ‘B’ was not declared in this scope
   15 |                                 cout<<C<<"<"<<a<<"<"<<B<<endl;//231
      |                                                       ^
foo.cc:15:58: error: ‘endl’ was not declared in this scope
   15 |                                 cout<<C<<"<"<<a<<"<"<<B<<endl;//231
      |                                                          ^~~~
foo.cc:15:58: note: ‘std::endl’ is defined in header ‘<ostream>’; did you forget to ‘#include <ostream>’?
foo.cc:19:25: error: ‘cout’ was not declared in this scope
   19 |                         cout<<b<<"<"<<a<<"<"<<c<<endl;//213
      |                         ^~~~
foo.cc:19:25: note: ‘std::cout’ is defined in header ‘<iostream>’; did you forget to ‘#include <iostream>’?
foo.cc:19:50: error: ‘endl’ was not declared in this scope
   19 |                         cout<<b<<"<"<<a<<"<"<<c<<endl;//213
      |                                                  ^~~~
foo.cc:19:50: note: ‘std::endl’ is defined in header ‘<ostream>’; did you forget to ‘#include <ostream>’?
foo.cc:23:33: error: ‘cout’ was not declared in this scope
   23 |                                 cout<<b<<"<"<<c<<"<"<<a<<endl;//312
      |                                 ^~~~
foo.cc:23:33: note: ‘std::cout’ is defined in header ‘<iostream>’; did you forget to ‘#include <iostream>’?
foo.cc:23:58: error: ‘endl’ was not declared in this scope
   23 |                                 cout<<b<<"<"<<c<<"<"<<a<<endl;//312
      |                                                          ^~~~
foo.cc:23:58: note: ‘std::endl’ is defined in header ‘<ostream>’; did you forget to ‘#include <ostream>’?
foo.cc:25:33: error: ‘cout’ was not declared in this scope
   25 |                                 cout<<c<<"<"<<b<<"<"<<a<<endl;//321
      |                                 ^~~~
foo.cc:25:33: note: ‘std::cout’ is defined in header ‘<iostream>’; did you forget to ‘#include <iostream>’?
foo.cc:25:58: error: ‘endl’ was not declared in this scope
   25 |                                 cout<<c<<"<"<<b<<"<"<<a<<endl;//321
      |                                                          ^~~~
foo.cc:25:58: note: ‘std::endl’ is defined in header ‘<ostream>’; did you forget to ‘#include <ostream>’?
foo.cc:16:9: warning: this ‘else’ clause does not guard... [-Wmisleading-indentation]
   16 |         else
      |         ^~~~
foo.cc:26:17: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the ‘else’
   26 |                 return  0;
      |                 ^~~~~~