Main.cc:2:7: error: expected nested-name-specifier before ‘namespce’ using namespce std; ^~~~~~~~ Main.cc: In function ‘int main()’: Main.cc:5:5: error: ‘cin’ was not declared in this scope cin>>a>>b; ^~~ Main.cc:5:5: note: suggested alternative: In file included from /usr/include/x86_64-linux-gnu/c++/7/bits/stdc++.h:75:0, from Main.cc:1: /usr/include/c++/7/iostream:60:18: note: ‘std::cin’ extern istream cin; /// Linked to standard input ^~~ Main.cc:7:5: error: ‘cout’ was not declared in this scope cout<