Elevator Floor Patrol Limit

A building's elevator logs every floor it stops at during a single overnight run, in visiting order, as an array of floor numbers. A maintenance inspector wants to find the longest unbroken stretch of consecutive stops in that log forming a valid inspection window: the window must begin on an even-numbered floor, every floor number inside the window must be at most a given maintenance cap (floors above the cap are sealed off and could not have been safely visited), and, moving from each stop to the very next stop inside the window, the floor's parity (even or odd) must flip every single time.

Given the elevator's full stop log and the maintenance cap, find the length of the longest inspection window.

Input format

• Line 1: two integers n and cap, separated by a space — the number of logged stops and the maintenance cap.
• Line 2: n integers floor[0..n-1] — the floor numbers, in visiting order.

Output format

Print a single integer: the length of the longest inspection window, or 0 if no window of length at least 1 exists (i.e., no logged floor is both even and within the cap).

Constraints

• 1 <= n <= 100000
• 0 <= floor[i] <= 100000 for every i
• 0 <= cap <= 100000

4 5
3 2 5 4

3

2 2
1 2

1