/in/foo.cc: In instantiation of 'disjointSetUnion<LEN>::disjointSetUnion() [with long unsigned int LEN = 30000]':
/in/foo.cc:13:26:   required from here
/in/foo.cc:6:39: warning: comparison of integer expressions of different signedness: 'int' and 'long unsigned int' [-Wsign-compare]
    6 |     disjointSetUnion(){for(int i = 0;i<LEN;i++)fa[i]=i,sz[i]=1;}
      |                                      ~^~~~