Background

Description

(A variation on the sumHeights problem.) We have an array of heights, representing the altitude along a walking trail. Given start/end indexes into the array, return the number of "big" steps for a walk starting at the start index and ending at the end index. We'll say that step is big if it is 5 or more up or down. The start end end index will both be valid indexes into the array with start <= end.

Format

Input

Output

Samples

[5 3 6 7 2] 2 4

1

[5 3 6 7 2] 0 1

0

[5 3 6 7 2] 0 4

1

Limitation

1s, 1024KiB for each test case.