foo.cc: In function 'dts::ll dts::bfs()':
foo.cc:43:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for (ll i=0;i<e[now].size();i++)
                         ~^~~~~~~~~~~~~~
foo.cc: In function 'void dts::main()':
foo.cc:73:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
                 scanf("%lld%lld%lld",&a[i],&b[i],&c[i]);
                 ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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