B'You have a permutation p of integers from 1 to n . You have a strength of s and will perform the following operation some times: It can be shown that no matter what i you have chosen, p will be a permutation of integers from 1 to |p| after all operations. You want to be able to transform p into the empty permutation. Find the minimum strength s that will allow you to do so. The first line of input contains a single integer n ( 1 <= q n <= q 5 cdot 10^5 ) -- the length of the permutation p . The second line of input conatains n integers p_1, p_2, ldots, p_n ( 1 <= q p_i <= q n ) -- the elements of the permutation p . It is guaranteed that all elements in p are distinct. Print the minimum strength s required. In the first test case, the minimum s required is 1 . Here is how we can transform p into the empty permutation with s=1 : It can be shown that with s=0 , it is impossible to transform p into the empty permutation. '...