def key_of_min(d):
  return min(d, key = d.get)

key_of_min({'a':4, 'b':0, 'c':13}) # b

import os

# Get the current directory
current_dir = os.getcwd()

# Loop through each file in the current directory
for filename in os.listdir(current_dir):

    # Check if the file name starts with a number followed by a period and a space
    if filename[0].isdigit() and filename[1] == '.' and filename[2] == ' ':
        
        # Remove the number, period, and space from the file name
        new_filename = filename[3:]
        
        # Rename the file
        os.rename(os.path.join(current_dir, filename), os.path.join(current_dir, new_filename))

# Python program to reverse a linked list
# Time Complexity : O(n)
# Space Complexity : O(n) as 'next'
#variable is getting created in each loop.

# Node class


class Node:

	# Constructor to initialize the node object
	def __init__(self, data):
		self.data = data
		self.next = None


class LinkedList:

	# Function to initialize head
	def __init__(self):
		self.head = None

	# Function to reverse the linked list
	def reverse(self):
		prev = None
		current = self.head
		while(current is not None):
			next = current.next
			current.next = prev
			prev = current
			current = next
		self.head = prev

	# Function to insert a new node at the beginning
	def push(self, new_data):
		new_node = Node(new_data)
		new_node.next = self.head
		self.head = new_node

	# Utility function to print the linked LinkedList
	def printList(self):
		temp = self.head
		while(temp):
			print temp.data,
			temp = temp.next


# Driver program to test above functions
llist = LinkedList()
llist.push(20)
llist.push(4)
llist.push(15)
llist.push(85)

print "Given Linked List"
llist.printList()
llist.reverse()
print "\nReversed Linked List"
llist.printList()

# Prompt user for base and height
base = float(input("Enter the base of the triangle: "))
height = float(input("Enter the height of the triangle: "))

# Calculate the area
area = (base * height) / 2

# Display the result
print("The area of the triangle is:", area)

weigh = lambda a,b: sum(b)-sum(a)
FindCoin = lambda A: 0 if (n := len(A)) == 1 else (m := n//3) * (w := 1 + weigh(A[:m], A[2*m:])) + FindCoin(A[m*w:m*(w+1)])
print(FindCoin([1,1,1,1,1,1,1,2,1]))