Dynamic Range Sum Operations

You are given an initially empty list of integers. Your task is to process n operations on this list. There are three types of operations:

• 1 x: Append the integer x to the end of the list.
• 2 p: Remove the integer at index p (0-indexed) from the list. If p is invalid (i.e. not in the current list), this operation has no effect.
• 3 a b: Query and output the sum of the subarray from index a to index b (inclusive). If the indices are out of range or if a > b, output 0.

Formally, let the list be denoted by nums, then the query result is given by:

$$ \text{result} = \begin{cases} \sum_{i=a}^{b} \text{nums}[i] & \text{if } 0 \leq a \leq b < |\text{nums}|, \\ 0 & \text{otherwise.} \end{cases} $$

Process all the operations and for each query operation (the ones starting with 3), print the result on a new line.

inputFormat

The first line of input contains an integer n which stands for the number of operations.

Each of the following n lines contains an operation in one of the following formats:

• 1 x — append integer x to the list.
• 2 p — remove the element at index p (0-indexed) from the list.
• 3 a b — output the sum of elements from index a to b (inclusive).

outputFormat

For each query operation (those starting with 3), output the computed sum on a separate line.

## sample

6
1 5
1 3
1 8
3 0 2
2 1
3 0 1

16
13

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