How Many Times Was It Rotated?

A sorted list with no repeated values was rotated to the left by some amount (for example [1, 2, 3, 4, 5] rotated left by 2 is [3, 4, 5, 1, 2]). Return that amount, a number from 0 to len(nums) - 1.

Examples

Example 1

Input:

rotation_count([3, 4, 5, 1, 2])

Output:

3

Example 2

Input:

rotation_count([1, 2, 3])

Output:

0

Constraints

• 1 <= len(nums) <= 2 * 10**5
• All values are different; the list is a sorted list rotated left.
• -10**9 <= nums[i] <= 10**9
• The big tests count how many values your code reads from the list (the limit is stated in the failure message). Reading every value, or using in, .index, .count, min or sorted on the whole list, fails them.