foo.cc: In function 'int dfs(int, int)':
foo.cc:14:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   14 |         for(int i=0; i!=a[x].size(); i++) {
      |                      ~^~~~~~~~~~~~~

Found 20 testcases.
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