/in/foo.cc: In function 'int main()':
/in/foo.cc:5:5: error: 'cin' was not declared in this scope
    5 |     cin>>n;
      |     ^~~
/in/foo.cc:1:1: note: 'std::cin' is defined in header '<iostream>'; did you forget to '#include <iostream>'?
  +++ |+#include <iostream>
    1 | using namespace std;
/in/foo.cc:16:13: error: 'cout' was not declared in this scope
   16 |             cout<<a[i][j]<<" ";
      |             ^~~~
/in/foo.cc:16:13: note: 'std::cout' is defined in header '<iostream>'; did you forget to '#include <iostream>'?
/in/foo.cc:17:9: error: 'cout' was not declared in this scope
   17 |         cout<<"\n";
      |         ^~~~
/in/foo.cc:17:9: note: 'std::cout' is defined in header '<iostream>'; did you forget to '#include <iostream>'?