/in/foo.cc: In function 'int find(int)':
/in/foo.cc:12:2: error: reference to 'rank' is ambiguous
  rank[u]=(rank[u]+rank[t])%3;
  ^~~~
/in/foo.cc:7:9: note: candidates are: int rank [50004]
 int n,k,rank[50004],f[50004],ans;
         ^~~~
In file included from /usr/include/c++/7/bits/move.h:54:0,
                 from /usr/include/c++/7/bits/nested_exception.h:40,
                 from /usr/include/c++/7/exception:143,
                 from /usr/include/c++/7/ios:39,
                 from /usr/include/c++/7/ostream:38,
                 from /usr/include/c++/7/iostream:39,
                 from /in/foo.cc:1:
/usr/include/c++/7/type_traits:1471:12: note:                 template<class> struct std::rank
     struct rank
            ^~~~
/in/foo.cc:12:11: error: reference to 'rank' is ambiguous
  rank[u]=(rank[u]+rank[t])%3;
           ^~~~
/in/foo.cc:7:9: note: candidates are: int rank [50004]
 int n,k,rank[50004],f[50004],ans;
         ^~~~
In file included from /usr/include/c++/7/bits/move.h:54:0,
                 from /usr/include/c++/7/bits/nested_exception.h:40,
                 from /usr/include/c++/7/exception:143,
                 from /usr/include/c++/7/ios:39,
                 from /usr/include/c++/7/ostream:38,
                 from /usr/include/c++/7/iostream:39,
                 from /in/foo.cc:1:
/usr/include/c++/7/type_traits:1471:12: note:                 template<class> struct std::rank
     struct rank
            ^~~~
/in/foo.cc:12:19: error: reference to 'rank' is ambiguous
  rank[u]=(rank[u]+rank[t])%3;
                   ^~~~
/in/foo.cc:7:9: note: candidates are: int rank [50004]
 int n,k,rank[50004],f[50004],ans;
         ^~~~
In file included from /usr/include/c++/7/bits/move.h:54:0,
                 from /usr/include/c++/7/bits/nested_exception.h:40,
                 from /usr/include/c++/7/exception:143,
                 from /usr/include/c++/7/ios:39,
                 from /usr/include/c++/7/ostream:38,
                 from /usr/include/c++/7/iostream:39,
                 from /in/foo.cc:1:
/usr/include/c++/7/type_traits:1471:12: note:                 template<class> struct std::rank
     struct rank
            ^~~~
/in/foo.cc: In function 'void merge(int, int, int)':
/in/foo.cc:18:2: error: reference to 'rank' is ambiguous
  rank[fy]=(rank[z]-rank[y]+x+2)%3;
  ^~~~
/in/foo.cc:7:9: note: candidates are: int rank [50004]
 int n,k,rank[50004],f[50004],ans;
         ^~~~
In file included from /usr/include/c++/7/bits/move.h:54:0,
                 from /usr/include/c++/7/bits/nested_exception.h:40,
                 from /usr/include/c++/7/exception:143,
                 from /usr/include/c++/7/ios:39,
                 from /usr/include/c++/7/ostream:38,
                 from /usr/include/c++/7/iostream:39,
                 from /in/foo.cc:1:
/usr/include/c++/7/type_traits:1471:12: note:                 template<class> struct std::rank
     struct rank
            ^~~~
/in/foo.cc:18:12: error: reference to 'rank' is ambiguous
  rank[fy]=(rank[z]-rank[y]+x+2)%3;
            ^~~~
/in/foo.cc:7:9: note: candidates are: int rank [50004]
 int n,k,rank[50004],f[50004],ans;
         ^~~~
In file included from /usr/include/c++/7/bits/move.h:54:0,
                 from /usr/include/c++/7/bits/nested_exception.h:40,
                 from /usr/include/c++/7/exception:143,
                 from /usr/include/c++/7/ios:39,
                 from /usr/include/c++/7/ostream:38,
                 from /usr/include/c++/7/iostream:39,
                 from /in/foo.cc:1:
/usr/include/c++/7/type_traits:1471:12: note:                 template<class> struct std::rank
     struct rank
            ^~~~
/in/foo.cc:18:20: error: reference to 'rank' is ambiguous
  rank[fy]=(rank[z]-rank[y]+x+2)%3;
                    ^~~~
/in/foo.cc:7:9: note: candidates are: int rank [50004]
 int n,k,rank[50004],f[50004],ans;
         ^~~~
In file included from /usr/include/c++/7/bits/move.h:54:0,
                 from /usr/include/c++/7/bits/nested_exception.h:40,
                 from /usr/include/c++/7/exception:143,
                 from /usr/include/c++/7/ios:39,
                 from /usr/include/c++/7/ostream:38,
                 from /usr/include/c++/7/iostream:39,
                 from /in/foo.cc:1:
/usr/include/c++/7/type_traits:1471:12: note:                 template<class> struct std::rank
     struct rank
            ^~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:32:8: error: reference to 'rank' is ambiguous
    if((rank[y]-rank[x])%3==x-1)ans++;
        ^~~~
/in/foo.cc:7:9: note: candidates are: int rank [50004]
 int n,k,rank[50004],f[50004],ans;
         ^~~~
In file included from /usr/include/c++/7/bits/move.h:54:0,
                 from /usr/include/c++/7/bits/nested_exception.h:40,
                 from /usr/include/c++/7/exception:143,
                 from /usr/include/c++/7/ios:39,
                 from /usr/include/c++/7/ostream:38,
                 from /usr/include/c++/7/iostream:39,
                 from /in/foo.cc:1:
/usr/include/c++/7/type_traits:1471:12: note:                 template<class> struct std::rank
     struct rank
            ^~~~
/in/foo.cc:32:16: error: reference to 'rank' is ambiguous
    if((rank[y]-rank[x])%3==x-1)ans++;
                ^~~~
/in/foo.cc:7:9: note: candidates are: int rank [50004]
 int n,k,rank[50004],f[50004],ans;
         ^~~~
In file included from /usr/include/c++/7/bits/move.h:54:0,
                 from /usr/include/c++/7/bits/nested_exception.h:40,
                 from /usr/include/c++/7/exception:143,
                 from /usr/include/c++/7/ios:39,
                 from /usr/include/c++/7/ostream:38,
                 from /usr/include/c++/7/iostream:39,
                 from /in/foo.cc:1:
/usr/include/c++/7/type_traits:1471:12: note:                 template<class> struct std::rank
     struct rank
            ^~~~