B'You are given a permutation p_1, p_2, ... , p_n of [1, 2, ... , n] . You can perform the following operation some (possibly 0 ) times: Sort the permutation in at most 10^6 operations. You do not need to minimize the number of operations. The first line contains a single integer n ( 2 <= n <= 3 cdot 10^5 ) -- the length of the permutation. The second line contains n integers p_1, p_2, ldots, p_n ( 1 <= p_i <= n , the p_i are distinct) -- the permutation before performing the operations. Output your operations in the following format. The first line should contain an integer k ( 0 <= k <= 10^6 ) -- the number of operations. The next k lines represent the k operations in order. Each of these k lines should contain two integers l and r ( 1 <= q l < r <= q n , r-l+1 must be even) -- the corresponding operation consists in choosing the subarray [l, r] and swapping its elements according to the problem statement. After all the operations, a_i = i must be true for each i ( 1 <= q i <= q n ). In the first test: In the second test, the permutation is already sorted, so you do not need to perform any operation. '...