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Time Limit: 1.0 Seconds Memory Limit: 65536K

Total Runs: 798 Accepted Runs: 559 Multiple test files

Farmer John tries to keep the cows sharp by letting them play with
intellectual toys. One of the larger toys is the lights in the barn.
Each of the *N* (2 ≤ *N* ≤ 500) cow stalls conveniently numbered
1..*N* has a colorful light above it.

At the beginning of the evening, all the lights are off. The cows
control the lights with a set of *N* pushbutton switches that toggle
the lights; pushing switch *i* changes the state of light *i* from off
to on or from on to off.

The cows read and execute a list of *M* (1 ≤ *M* ≤ 2,000)
operations expressed as one of two integers (0 ≤ operation ≤ 1).
The first operation (denoted by a 0 command) includes two subsequent
integers *S_i* and *E_i* (1 ≤ *S_i* ≤ *E_i* ≤
*N*) that indicate a starting switch and ending switch. They execute
the operation by pushing each pushbutton from *S_i* through *E_i*
inclusive exactly once.

The second operation (denoted by a 1 command) asks the cows to count
how many lights are on in the range given by two integers *S_i* and
*E_i* (1 ≤ *S_i* ≤ *E_i* ≤ *N*) which specify the
inclusive range in which the cows should count the number of lights that are on.

Help FJ ensure the cows are getting the correct answer by processing the list and producing the proper counts.

* Line 1: Two space-separated integers: *N* and *M*

* Lines 2..*M*+1: Each line represents an operation with three
space-separated integers: operation, *S_i*, and *E_i*

* Lines 1..number of queries: For each output query, print the count as an integer by itself on a single line.

4 5 0 1 2 0 2 4 1 2 3 0 2 4 1 1 4

1 2

In the sample, there are four lights; five commands. Here is the sequence that should be processed:

Lights 1 2 3 4 Init: O O O O O = off * = on 0 1 2 -> * * O O toggle lights 1 and 2 0 2 4 -> * O * * 1 2 3 -> 1 count the number of lit lights in range 2..3 0 2 4 -> * * O O toggle lights 2, 3, and 4 1 1 4 -> 2 count the number of lit lights in the range 1..4

Maintance:Fxz. Developer: SuperHacker, G.D.Retop, Fxz