foo.cc: In function 'int main()':
foo.cc:20:5: error: 'cin' was not declared in this scope
   20 |     cin >> Yisbn;
      |     ^~~
foo.cc:1:1: note: 'std::cin' is defined in header '<iostream>'; did you forget to '#include <iostream>'?
  +++ |+#include <iostream>
    1 | using namespace std;
foo.cc:21:20: error: 'cout' was not declared in this scope
   21 |     if (jug(Yisbn))cout << "Right";
      |                    ^~~~
foo.cc:21:20: note: 'std::cout' is defined in header '<iostream>'; did you forget to '#include <iostream>'?
foo.cc:24:9: error: 'cout' was not declared in this scope
   24 |         cout << Yisbn;
      |         ^~~~
foo.cc:24:9: note: 'std::cout' is defined in header '<iostream>'; did you forget to '#include <iostream>'?

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