# Write a Python program to find the index position of the largest value smaller than a given number in a sorted list using Binary Search (bisect).  
 from bisect import bisect_left  
def Binary_Search(l, x): 
    i = bisect_left(l, x) 
    if i: 
        return (i-1) 
    else: 
        return -1  
nums = [1, 2, 3, 4, 8, 8, 10, 12] 
x = 5 
num_position  = Binary_Search(nums, x) 
if num_position  == -1: 
    print("Not found..!") 
else: 
    print("Largest value smaller than ", x, " is at index ", num_position )
