Maintaining a Sequence

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Points: 12 (partial)
Time limit: 2.0s
Memory limit: 128M

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Problem type

Please write a program that maintains a sequence, supporting the following operations:

Operation Input Format Description
1. Reverse REVERSE Reverse the entire sequence.
2. Get Sum GET-SUM posi tot Starting at the posi-th number in the current sequence, output the sum of tot consecutive numbers.
3. Max Sum MAX-SUM Output the largest sum of any (non-empty) consecutive subsequence of the current sequence.

Input Specification

The first line of input contains two integers N and M, where N is the initial length of the sequence and M is the number of operations.

The second line of input contains N integers, describing the initial sequence.

For the next M lines, each line will contain a command in one of the formats described above.

Output Specification

For each GET-SUM or MAX-SUM operation in the input, output the result of the query on a separate line.

Sample Input

9 7
2 -6 3 5 1 -5 -3 6 3
GET-SUM 5 4
REVERSE
GET-SUM 5 4
MAX-SUM
GET-SUM 3 6
REVERSE
GET-SUM 1 2

Sample Output

-1
3
10
-5
-4

Constraints

The data in the input is guaranteed to be valid, and will always refer to existing positions in the sequence.

In test data worth 40\% of the points, N \le 100.
In test data worth 100\% of the points, N \le 100 000.

In test data worth 100\% of the points, the value of any number in the sequence will be in the range [-10 000, 10 000].
In test data worth 100\% of the points, M \le 100 000.


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