CF85D Sum of Medians

In one well-known algorithm of finding the $ k $-th order statistics we should divide all elements into groups of five consecutive elements and find the median of each five. A median is called the middle element of a sorted array (it's the third largest element for a group of five). To increase the algorithm's performance speed on a modern video card, you should be able to find a sum of medians in each five of the array. A sum of medians of a sorted $ k $-element set $ S={a_{1},a_{2},...,a_{k}} $ , where $ a_{1}

The first line contains number $ n $ ( $ 1\le n\le 10^{5} $ ), the number of operations performed. Then each of $ n $ lines contains the description of one of the three operations: - add $ x $ — add the element $ x $ to the set; - del $ x $ — delete the element $ x $ from the set; - sum — find the sum of medians of the set. For any add $ x $ operation it is true that the element $ x $ is not included in the set directly before the operation. For any del $ x $ operation it is true that the element $ x $ is included in the set directly before the operation. All the numbers in the input are positive integers, not exceeding $ 10^{9} $ .

For each operation sum print on the single line the sum of medians of the current set. If the set is empty, print $0$. Please, do not use the %lld specificator to read or write 64-bit integers in C++. It is preferred to use the cin, cout streams (also you may use the %I64d specificator).