Dynamic Range Sum Query with Segment Tree

You are given an array of integers and a series of queries. There are two types of queries:

• Update Query: 1 X Y — Update the element at position X to the value Y.
• Sum Query: 2 L R — Compute the sum of the subarray from index L to R (inclusive).

Your task is to process these queries efficiently. A common data structure to handle such range queries and updates is the Segment Tree.

The sum for a query of type 2 is defined mathematically as \[ S = \sum_{i=L}^{R} a_i \] where \(a_i\) represents the element at the i-th position.

Input is taken from stdin and output should be printed to stdout. For each query of type 2, print the computed sum on a new line.

inputFormat

The first line contains two space-separated integers N and Q where N is the number of elements in the array, and Q is the number of queries.

The second line contains N space-separated integers representing the initial array.

The following Q lines each contain a query in one of the following formats:

• 1 X Y — Update the element at position X to Y.
• 2 L R — Output the sum of the subarray from L to R.

outputFormat

For each query of type 2, output a single line containing the sum of the specified subarray.

## sample

5 5
1 2 3 4 5
2 1 3
1 3 10
2 2 5
1 5 6
2 1 5

6
21
23

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