/in/foo.cc: In function 'void dfs(int, int)':
/in/foo.cc:29:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (i=0;i<bi[x].size();i++)
           ~^~~~~~~~~~~~~
/in/foo.cc: In function 'bool dfs2(long long int, long long int)':
/in/foo.cc:52:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (i=0;i<bi[x].size();i++)
           ~^~~~~~~~~~~~~
/in/foo.cc: In function 'bool check(long long int)':
/in/foo.cc:79:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (i=0;i<bi[1].size();i++)
           ~^~~~~~~~~~~~~
/in/foo.cc:93:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (j=0;j<seq[bi[1][i].y].size();j++)
            ~^~~~~~~~~~~~~~~~~~~~~~~
/in/foo.cc:106:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (i=0;i<ned.size();i++)
           ~^~~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:126:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (i=0;i<bi[1].size();i++)
           ~^~~~~~~~~~~~~