B"So you decided to hold a contest on Codeforces. You prepared the problems: statements, solutions, checkers, validators, tests... Suddenly, your coordinator asks you to change all your tests to multiple testcases in the easiest problem! Initially, each test in that problem is just an array. The maximum size of an array is k . For simplicity, the contents of arrays don't matter. You have n tests -- the i -th test is an array of size m_i ( 1 <= m_i <= k ). Your coordinator asks you to distribute all of your arrays into multiple testcases. Each testcase can include multiple arrays. However, each testcase should include no more than c_1 arrays of size greater than or equal to 1 ( ge 1 ), no more than c_2 arrays of size greater than or equal to 2 , ... , no more than c_k arrays of size greater than or equal to k . Also, c_1 ge c_2 ge ... ge c_k . So now your goal is to create the new testcases in such a way that: Print the minimum possible number of testcases you can achieve and the sizes of arrays included in each testcase. The first line contains two integers n and k ( 1 <= n, k <= 2 cdot 10^5 ) -- the number of initial tests and the limit for the size of each array. The second line contains n integers m_1, m_2, ... , m_n ( 1 <= m_i <= k ) -- the sizes of the arrays in the original tests. The third line contains k integers c_1, c_2, ... , c_k ( n ge c_1 ge c_2 ge ... ge c_k ge 1 ); c_i is the maximum number of arrays of size greater than or equal to i you can have in a single testcase. In the first line print a single integer ans ( 1 <= ans <= n ) -- the minimum number of testcases you can achieve. Each of the next ans lines should contain the description of a testcase in the following format: t a_1 a_2 ... a_{t} ( 1 <= t <= n ) -- the testc"...