foo.cc: In function 'int main(int, char**, char**)':
foo.cc:21:28: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   21 |         if (edge[i].size() >= k) {
      |             ~~~~~~~~~~~~~~~^~~~

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