foo.cc: In function 'int main(int, char**)':
foo.cc:23:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, std::__cxx11::basic_string<char> > >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   23 |  for(int i = 0; i < v.size(); i++) {
      |                 ~~^~~~~~~~~~

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