B'You are given an array of n integers a_1 , a_2 , ..., a_n , and a set b of k distinct integers from 1 to n . In one operation, you may choose two integers i and x ( 1 <= i <= n , x can be any integer) and assign a_i := x . This operation can be done only if i does not belong to the set b . Calculate the minimum number of operations you should perform so the array a is increasing (that is, a_1 < a_2 < a_3 < ... < a_n ), or report that it is impossible. The first line contains two integers n and k ( 1 <= n <= 5 cdot 10^5 , 0 <= k <= n ) -- the size of the array a and the set b , respectively. The second line contains n integers a_1 , a_2 , ..., a_n ( 1 <= a_i <= 10^9 ). Then, if k ne 0 , the third line follows, containing k integers b_1 , b_2 , ..., b_k ( 1 <= b_1 < b_2 < ... < b_k <= n ). If k = 0 , this line is skipped. If it is impossible to make the array a increasing using the given operations, print -1 . Otherwise, print one integer -- the minimum number of operations you have to perform. '...