foo.cc: In function 'int main()':
foo.cc:6:4: error: 'cin' was not declared in this scope
    cin>>a;
    ^~~
foo.cc:6:4: note: suggested alternative:
In file included from foo.cc:1:0:
/usr/include/c++/7/iostream:60:18: note:   'std::cin'
   extern istream cin;  /// Linked to standard input
                  ^~~
foo.cc:7:8: error: lvalue required as left operand of assignment
    m+3=n;
        ^
foo.cc:10:3: error: 'cout' was not declared in this scope
   cout<<"Yes ";
   ^~~~
foo.cc:10:3: note: suggested alternative:
In file included from foo.cc:1:0:
/usr/include/c++/7/iostream:61:18: note:   'std::cout'
   extern ostream cout;  /// Linked to standard output
                  ^~~~
foo.cc:14:3: error: 'cout' was not declared in this scope
   cout<<"No"; 
   ^~~~
foo.cc:14:3: note: suggested alternative:
In file included from foo.cc:1:0:
/usr/include/c++/7/iostream:61:18: note:   'std::cout'
   extern ostream cout;  /// Linked to standard output
                  ^~~~

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