foo.cc: In function 'std::ostream& operator<<(std::ostream&, Vector)':
foo.cc:62:2: warning: no return statement in function returning non-void [-Wreturn-type]
   62 |  }
      |  ^
foo.cc: In member function 'void VectorArray::Output()':
foo.cc:81:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<Vector>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   81 |   for(int i = 0;i<v.size();i++)
      |                 ~^~~~~~~~~

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