Mã chấm: 267989

Main.cc:3:7: error: expected nested-name-specifier before ‘manespace’
 using manespace std;
       ^~~~~~~~~
Main.cc: In function ‘int main()’:
Main.cc:7:5: error: ‘cin’ was not declared in this scope
     cin >> a >> b >> x >> y;
     ^~~
Main.cc:7:5: 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:9:5: error: ‘cout’ was not declared in this scope
     cout << (a*x)+(b*y);
     ^~~~
Main.cc:9:5: 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:61:18: note:   ‘std::cout’
   extern ostream cout;  /// Linked to standard output
                  ^~~~