/in/foo.cc: In function 'int main()':
/in/foo.cc:5:2: error: 'cin' was not declared in this scope
cin>>n;
^~~
/in/foo.cc:12:4: error: 'cout' was not declared in this scope
cout<<" ";
^~~~
/in/foo.cc:17:4: error: 'cout' was not declared in this scope
cout<<"#";
^~~~
/in/foo.cc:21:3: error: 'cout' was not declared in this scope
cout<<endl;
^~~~
/in/foo.cc:21:9: error: 'endl' was not declared in this scope
cout<<endl;
^~~~
/in/foo.cc:4:7: warning: unused variable 'a' [-Wunused-variable]
char a='a';
^