B'A binary string is a string where every character is texttt{0} or texttt{1} . Call a binary string decent if it has an equal number of texttt{0} s and texttt{1} s. Initially, you have an infinite binary string t whose characters are all texttt{0} s. You are given a sequence a of n updates, where a_i indicates that the character at index a_i will be flipped ( texttt{0} <= ftrightarrow texttt{1} ). You need to keep and modify after each update a set S of disjoint ranges such that: You only need to output the ranges that are added to or removed from S after each update. You can only add or remove ranges from S at most mathbf{10^6} times. More formally, let S_i be the set of ranges after the i -th update, where S_0 = varnothing (the empty set). Define X_i to be the set of ranges removed after update i , and Y_i to be the set of ranges added after update i . Then for 1 <= q i <= q n , S_i = (S_{i - 1} setminus X_i) cup Y_i . The following should hold for all 1 <= q i <= q n : The first line contains a single integer n ( 1 <= q n <= q 2 cdot 10^5 ) -- the number of updates. The next n lines each contain a single integer a_i ( 1 <= q a_i <= q 2 cdot 10^5 ) -- the index of the i -th update to the string. After the i -th update, first output a single integer x_i -- the number of ranges to be removed from S after update i . In the following x_i lines, output two integers l and r ( 1 <= q l < r <= q 10^6 ), which denotes that the range [l,r] should be removed from S . Each of these ranges should be distinct and be part of S . In the next line, output a single integer y_i -- the number of ranges to be added to S after update i . In the following y_i lines, output two integers l and r ( '...