#!/usr/bin/env python3

def binary_search(arr, x):
    # Left index
    l = 0
    r = len(arr) - 1

    while l <= r:
        mid = l + (r - l) / 2

        # Check if x == mid
        if arr[mid] == x:
            return mid

        elif arr[mid] < x:
            l = mid + 1

        else:
            l = mid - 1
    return -1

l = list(range(255))
print(l)
print(255, binary_search(l,255))
print(200, binary_search(l,200))

l = list(range(0, 255, 3))
print(l)
print(255, binary_search(l,200))
print(72, binary_search(l,72))
print(19, binary_search(l,19))