foo.cc: In function 'll dfs(ll)':
foo.cc:14:16: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   14 |  for (i = 0; i < e[p].size(); i++)
      |              ~~^~~~~~~~~~~~~
foo.cc: In function 'int main()':
foo.cc:26:8: warning: unused variable 'j' [-Wunused-variable]
   26 |  ll i, j, k, u, v;
      |        ^
foo.cc:26:11: warning: unused variable 'k' [-Wunused-variable]
   26 |  ll i, j, k, u, v;
      |           ^

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