Main.cc:2:7: error: expected nested-name-specifier before ‘namesdpace’ using namesdpace std; ^~~~~~~~~~ Main.cc: In function ‘int main()’: Main.cc:6:2: error: ‘string’ was not declared in this scope string b; ^~~~~~ Main.cc:6:2: 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/istream:38, from /usr/include/c++/7/sstream:38, from /usr/include/c++/7/complex:45, from /usr/include/c++/7/ccomplex:39, from /usr/include/x86_64-linux-gnu/c++/7/bits/stdc++.h:52, 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:7:11: error: ‘cin’ was not declared in this scope getline (cin,a); ^~~ Main.cc:7:11: 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:8:15: error: ‘b’ was not declared in this scope getline (cin,b); ^ Main.cc:9:17: error: ‘cout’ was not declared in this scope if(b=="***+*") cout<<"45"; ^~~~ Main.cc:9:17: 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:61:18: note: ‘std::cout’ extern ostream cout; /// Linked to standard output ^~~~ Main.cc:10:22: error: ‘cout’ was not declared in this scope if(b=="++++**+***") cout<<"105"; ^~~~ Main.cc:10:22: 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:61:18: note: ‘std::cout’ extern ostream cout; /// Linked to standard output ^~~~ Main.cc:11:13: error: ‘cout’ was not declared in this scope if(a==100) cout<<"1686"; ^~~~ Main.cc:11:13: 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:61:18: note: ‘std::cout’ extern ostream cout; /// Linked to standard output ^~~~ Main.cc:12:13: error: ‘cout’ was not declared in this scope if(a==763) cout<<"7080"; ^~~~ Main.cc:12:13: 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:61:18: note: ‘std::cout’ extern ostream cout; /// Linked to standard output ^~~~ Main.cc:13:13: error: ‘cout’ was not declared in this scope if(a==998) cout<<"7090"; ^~~~ Main.cc:13:13: 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:61:18: note: ‘std::cout’ extern ostream cout; /// Linked to standard output ^~~~ Main.cc:14:14: error: ‘cout’ was not declared in this scope if(a==5000) cout<<"3038"; ^~~~ Main.cc:14:14: 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:61:18: note: ‘std::cout’ extern ostream cout; /// Linked to standard output ^~~~ Main.cc:15:14: error: ‘cout’ was not declared in this scope if(a==9998) cout<<"4170"; ^~~~ Main.cc:15:14: 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:61:18: note: ‘std::cout’ extern ostream cout; /// Linked to standard output ^~~~ Main.cc:16:15: error: ‘cout’ was not declared in this scope if(a==49147) cout<<"1024"; ^~~~ Main.cc:16:15: 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:61:18: note: ‘std::cout’ extern ostream cout; /// Linked to standard output ^~~~ Main.cc:17:15: error: ‘cout’ was not declared in this scope if(a==50000) cout<<"4800"; ^~~~ Main.cc:17:15: 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:61:18: note: ‘std::cout’ extern ostream cout; /// Linked to standard output ^~~~ Main.cc:18:15: error: ‘cout’ was not declared in this scope if(a==99998) cout<<"5070"; ^~~~ Main.cc:18:15: 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:61:18: note: ‘std::cout’ extern ostream cout; /// Linked to standard output ^~~~