foo.cc: In function 'void dfs(long long int)':
foo.cc:12:22: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   12 |         for(int i=0;i<v[now].size();i++)
      |                     ~^~~~~~~~~~~~~~

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