Preparando MOJI
Masha meets a new friend and learns his phone number — $$$s$$$. She wants to remember it as soon as possible. The phone number — is a string of length $$$m$$$ that consists of digits from $$$0$$$ to $$$9$$$. The phone number may start with 0.
Masha already knows $$$n$$$ phone numbers (all numbers have the same length $$$m$$$). It will be easier for her to remember a new number if the $$$s$$$ is represented as segments of numbers she already knows. Each such segment must be of length at least $$$2$$$, otherwise there will be too many segments and Masha will get confused.
For example, Masha needs to remember the number: $$$s = $$$ '12345678' and she already knows $$$n = 4$$$ numbers: '12340219', '20215601', '56782022', '12300678'. You can represent $$$s$$$ as a $$$3$$$ segment: '1234' of number one, '56' of number two, and '78' of number three. There are other ways to represent $$$s$$$.
Masha asks you for help, she asks you to break the string $$$s$$$ into segments of length $$$2$$$ or more of the numbers she already knows. If there are several possible answers, print any of them.
The first line of input data contains an integer $$$t$$$ ($$$1 \le t \le 10^4$$$) —the number of test cases.
Before each test case there is a blank line. Then there is a line containing integers $$$n$$$ and $$$m$$$ ($$$1 \le n, m \le 10^3$$$) —the number of phone numbers that Masha knows and the number of digits in each phone number. Then follow $$$n$$$ line, $$$i$$$-th of which describes the $$$i$$$-th number that Masha knows. The next line contains the phone number of her new friend $$$s$$$.
Among the given $$$n+1$$$ phones, there may be duplicates (identical phones).
It is guaranteed that the sum of $$$n \cdot m$$$ ($$$n$$$ multiplied by $$$m$$$) values over all input test cases does not exceed $$$10^6$$$.
You need to print the answers to $$$t$$$ test cases. The first line of the answer should contain one number $$$k$$$, corresponding to the number of segments into which you split the phone number $$$s$$$. Print -1 if you cannot get such a split.
If the answer is yes, then follow $$$k$$$ lines containing triples of numbers $$$l, r, i$$$. Such triplets mean that the next $$$r-l+1$$$ digits of number $$$s$$$ are equal to a segment (substring) with boundaries $$$[l, r]$$$ of the phone under number $$$i$$$. Both the phones and the digits in them are numbered from $$$1$$$. Note that $$$r-l+1 \ge 2$$$ for all $$$k$$$ lines.
5 4 8 12340219 20215601 56782022 12300678 12345678 2 3 134 126 123 1 4 1210 1221 4 3 251 064 859 957 054 4 7 7968636 9486033 4614224 5454197 9482268
3 1 4 1 5 6 2 3 4 3 -1 2 1 2 1 2 3 1 -1 3 1 3 2 5 6 3 3 4 1
The example from the statement.
In the second case, it is impossible to represent by segments of known numbers of length 2 or more.
In the third case, you can get the segments '12' and '21' from the first phone number.