Main.cc:2:7: error: expected nested-name-specifier before ‘namesapce’ using namesapce std; ^~~~~~~~~ Main.cc: In function ‘int main()’: Main.cc:4:5: error: ‘string’ was not declared in this scope string n; ^~~~~~ Main.cc:4:5: note: suggested alternatives: In file included from /usr/include/c++/7/iosfwd:39:0, from /usr/include/c++/7/ios:38, from /usr/include/c++/7/ostream:38, from /usr/include/c++/7/iostream:39, from Main.cc:1: /usr/include/c++/7/bits/stringfwd.h:74:33: note: ‘std::__cxx11::string’ typedef basic_string string; ^~~~~~ /usr/include/c++/7/bits/stringfwd.h:74:33: note: ‘std::__cxx11::string’ 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++/7/iostream:60:18: note: ‘std::cin’ extern istream cin; /// Linked to standard input ^~~ Main.cc:5:10: error: ‘n’ was not declared in this scope cin>>n; ^ Main.cc:7:9: error: ‘cout’ was not declared in this scope cout<