In 2018, hosted by Nanjing University of Aeronautics and Astronautics (NUAA), the
International Collegiate Programming Contest (ICPC) regional was held in Nanjing again after a few years' gap. There were over

teams in the contest and team
Power of Two from Tsinghua University won the champion.
Two years have passed and after the great success in 2018 and 2019, NUAA continues to hold the ICPC Nanjing Regional in 2020. Although we can't gather in Nanjing this time due to the pandemic, we should still be grateful for the hard work done by all staff and volunteers for this contest. Thank you all for your great contribution to this contest!
In the 2018 contest, problem K, Kangaroo Puzzle, requires the contestants to construct an operation sequence for the game. Let's first recall the content of that problem:
Our dear friend, Kotori, also took part in the contest and submitted a code of randomized algorithm. To her surprise, this simple solution is judged as a correct answer. We now present her solution as follows:
#include <bits stdc++.h>
char s[5] = 'UDLR';
using namespace std;
int main()
{
srand(time(NULL));
for (int i = 1; i <= 50000; i++) putchar(s[rand() % 4]);
return 0;
}
For contestants who are not familiar with C and C++: the above code will output a random string of length

consisting only of characters 'U', 'D', 'L' and 'R', where each character has equal probability to appear in each position in the string.
Kotori suspects that things might not be that simple for this problem, so right now, in this
2020 ICPC Nanjing Regional contest, you need to construct an input data to hack her solution. Due to the randomness, your input data only needs to satisfy a successful hacking rate of at least

. Formally speaking, we've prepared

randomly generated string according Kotori's code and will use them as the controlling sequence against your answer. For your answer to be accepted there should be at least

times that after using your answer as the map of cells and the whole controlling sequence is executed, there are still kangaroos in different cells.
Note that your input data should be completely legal. That is to say,
- The map in your answer should not be larger than
; - Your answer should contain at least two empty cells;
- All empty cells in your answer should be reachable starting from any empty cell;
- No cycles consisting of empty cells are allowed.