Preparando MOJI
You are given a matrix, consisting of $$$n$$$ rows and $$$m$$$ columns. The $$$j$$$-th cell of the $$$i$$$-th row contains an integer $$$a_{ij}$$$.
First, you have to color each row of the matrix either red or blue in such a way that at least one row is colored red and at least one row is colored blue.
Then, you have to choose an integer $$$k$$$ ($$$1 \le k < m$$$) and cut the colored matrix in such a way that the first $$$k$$$ columns become a separate matrix (the left matrix) and the last $$$m-k$$$ columns become a separate matrix (the right matrix).
The coloring and the cut are called perfect if two properties hold:
Find any perfect coloring and cut, or report that there are none.
The first line contains a single integer $$$t$$$ ($$$1 \le t \le 1000$$$) — the number of testcases.
Then the descriptions of $$$t$$$ testcases follow.
The first line of each testcase contains two integers $$$n$$$ and $$$m$$$ ($$$2 \le n, m \le 5 \cdot 10^5$$$; $$$n \cdot m \le 10^6$$$) — the number of rows and the number of columns in the matrix, respectively.
The $$$i$$$-th of the next $$$n$$$ lines contains $$$m$$$ integers $$$a_{i1}, a_{i2}, \dots, a_{im}$$$ ($$$1 \le a_{ij} \le 10^6$$$).
The sum of $$$n \cdot m$$$ over all testcases doesn't exceed $$$10^6$$$.
For each testcase print an answer. If there are no perfect colorings and cuts in the matrix, then print "NO".
Otherwise, first, print "YES". Then a string, consisting of $$$n$$$ characters: the $$$i$$$-th character should be 'R' if the $$$i$$$-th row is colored red and 'B' if it's colored blue. The string should contain at least one 'R' and at least one 'B'. Finally, print an integer $$$k$$$ ($$$1 \le k < m$$$) — the number of columns from the left that are cut.
3 5 5 1 5 8 8 7 5 2 1 4 3 1 6 9 7 5 9 3 3 3 2 1 7 9 9 8 3 3 8 9 8 1 5 3 7 5 7 2 6 3 3 3 2 2 2 1 1 1 4 4 4
YES BRBRB 1 NO YES RB 3
The coloring and the cut for the first testcase: