In mathematics, interval is the difference between the largest number and the smallest number in an array.

To illustrate:

A = (3, 5, 7, 23, 11, 42, 80)

Interval of A = 80 - 3 = 77

Create a function that takes an array and returns ":)" if the interval of the array is equal to any other element; otherwise return ":(".

Examples

face_interval([1, 2, 5, 8, 3, 9]) ➞ ":)"
# Array interval is equal to one of the other elements.

face_interval([5, 2, 8, 3, 11]) ➞ ":("
# Array interval is not among the other elements.

face_interval("bruh") ➞ ":/"
# "bruh" is not an array. It's string.

Notes

• Arrays won't contain any duplicate numbers.
• If you're not given an array, return ":/"