numbers = [1,2,3,4,4,5,6,6,7,8,8,9,10,11,15]
element = 3
print (len(numbers))


def binary_search(numbers, element):
    mid = len(numbers)//2
    if element not in numbers:
        return (-float('inf'))
    if numbers[mid] == element:
        return mid
    if numbers[mid] > element:
        return binary_search(numbers[:mid], element)
    else:
        return mid + binary_search(numbers[mid:], element)
#        return ('større enn tallet i midta')
print (binary_search(numbers, element))