B"Little R is a magician who likes non-decreasing arrays. She has an array of length n , initially as a_1, ldots, a_n , in which each element is an integer between [1, m] . She wants it to be non-decreasing, i.e., a_1 <= q a_2 <= q ldots <= q a_n . To do this, she can perform several magic tricks. Little R has a fixed array b_1 ldots b_m of length m . Formally, let's define a trick as a procedure that does the following things in order: Little R wonders how many tricks are needed at least to make the initial array non-decreasing. If it is not possible with any amount of tricks, print -1 instead. Each test contains multiple test cases. The first line contains the number of test cases t ( 1 <= t <= 10^4 ). The description of the test cases follows. The first line of each test case contains two integers n and m ( 1 <= q n <= q 10^6 , 1 <= q m <= q 10^6 ) -- the length of the initial array and the range of the elements in the array. The second line of each test case contains n integers a_1, ldots, a_n ( 1 <= q a_i <= q m ) -- the initial array. The third line of each test case contains m integers b_1, ldots, b_m ( 1 <= q b_i <= q m ) -- the fixed magic array. It is guaranteed that the sum of n over all test cases does not exceed 10^6 and the sum of m over all test cases does not exceed 10^6 . For each test case, output a single integer: the minimum number of tricks needed, or -1 if it is impossible to make a_1, ldots, a_n non-decreasing. In the first case, the initial array a_1, ldots, a_n is [1, 6, 3, 7, 1] . You can choose S as follows: In the second case, it is impossible to make a_1, ldots, a_n non-decreasing. "...