/in/foo.cc: In function 'Bigint operator*(const Bigint&, const Bigint&)':
/in/foo.cc:24:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   24 |                 for(int i=0;i<a.num.size();i++)
      |                             ~^~~~~~~~~~~~~
/in/foo.cc:27:38: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   27 |                         for(int j=0;j<b.num.size();j++)
      |                                     ~^~~~~~~~~~~~~