Main.cc:2:1: error: 'suing' does not name a type suing namespace std; ^ Main.cc: In function 'int main()': Main.cc:5:5: error: 'cin' was not declared in this scope cin>>n; ^ Main.cc:5:5: note: suggested alternative: In file included from Main.cc:1:0: /usr/include/c++/5/iostream:60:18: note: 'std::cin' extern istream cin; /// Linked to standard input ^ Main.cc:16:1: error: 'cout' was not declared in this scope cout<