def number(arr,target):
    left = 0
    right = len(arr)-1
    while left <= right:
        mid = (left + right) // 2
        if arr[mid] == target:
            return min
        elif arr[mid] < target:
            left = mid + 1
        else:
            right = mid -1
    return -1

arr = [1,2,3,4,5,6,7,8,9]
print(number(arr,2))