/in/foo.cc: In function 'int main()':
/in/foo.cc:176:24: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
  176 |         if (ans.size() < i) ans.push_back(-1);
      |             ~~~~~~~~~~~^~~