There is some problem with checker.
The last two my submitions differs only in priority of directions ('d', 'u', 'r', 'l' and 'r', 'l', 'd', 'u', so result for second example was "dddrrrruLdlUUUluRR" and "rrdddrruLdlUUUluRR" respectively), and the first of this attempts was WA3 while the second one was WA2. Please fix this problem or add some requirements to make the answer to be unique.

Are u sure that your second answer is really "rrdddrruLdlUUUluRR"? Checker on my local system outputs 'ok' for 2nd test case on both answers.

my answer is
rrdddrruuLrddllluuurDlddrUluRddrruLruLddlluuRlddrruLrruLdldlluururDllddrUluurDlddrrUdlluurRlldRdrUUUluRR
i check it, it is right answer too
but a have WA2

test case #2 is the same test as Sample#2 ?

I rechecked answer just now. It was "rrdddrruLdlUUUluRR".

Everything seems to be ok now. I've submitted the same solution, and now I have TLE6...

Yes, the second test is sample.
There were some problems with checker. Now it's all right.
Old solutions will be rejudged soon.