By Ginés García Mateos, UM España
Our friend Victor participates as an instructor in an environmental volunteer program. His boss asked him to distribute N T-shirts to M volunteers, one T-shirt each volunteer, where N is multiple of six, and N ≥ M. There are the same number of T-shirts of each one of the six available sizes: XXL, XL, L, M , S, and XS. Victor has a little problem because only two sizes of the T-shirts suit each volunteer.
You must write a program to decide if Victor can distribute T-shirts in such a way that all volunteers get a T-shirt that suit them. If N ≠ M, there can be some remaining T-shirts.
The first line of the input contains the number of test cases.
For each test case, there is a line with two numbers N and M. N is multiple of 6, 1 ≤ N ≤ 36, and indicates the number of T-shirts. Number M, 1 ≤ M ≤ 30, indicates the number of volunteers, with N ≥ M. Subsequently, M lines are listed where each line contains, separated by one space, the two sizes that suit each volunteer (XXL, XL, L, M , S, or XS).
For each test case you are to print a line containing YES if there is, at least, one distribution where T-shirts suit all volunteers, or NO, in other case.
|Sample Input||Sample Output|