You are given two strings. In a single move, you can choose any of them, and delete the first (i.e. leftmost) character.

For Example:

* By applying a move to the string `"where"`, the result is the string `"here"`.
* By applying a move to the string `"a"`, the result is an empty string `""`.

Implement a function that calculates the minimum number of moves that should be performed to make the given strings equal.

## Notes

* Both strings consist of lowercase latin letters.
* If the string is already empty, you cannot perform any more delete operations.

Difficulty: EASY
Starter code: def shift_left(a, b):
	

Solutions:
def shift_left(a, b):
	r = len(a) + len(b)
	for i in range(-1, -min(len(a), len(b)) - 1, -1):
		if a[i] != b[i]:
			break
		r -= 2
	return r


def shift_left(a, b):
	r = 0
	while a != b:
		if len(b) > len(a):
			b = b[1:]
			r += 1
		else:
			a = a[1:]
			r += 1
	return r


def shift_left(a, b, n=0):
	if a == b:
		return n
	elif len(a) > len(b):
		return shift_left(a[1:], b, n + 1)
	else:
		return shift_left(a, b[1:], n + 1)


def shift_left(a, b):
	return min((i + j for i in range(len(a) + 1) for j in range(len(b) + 1) if a[i:] == b[j:]))


import os

def shift_left(a, b):
	x = os.path.commonprefix([a[::-1], b[::-1]])
	return len(a) + len(b) - len(x) * 2


def shift_left(a, b):
	while True:
		if a and b and (a[-1] == b[-1]):
			(a, b) = (a[:-1], b[:-1])
			continue
		return len(a) + len(b)


def shift_left(a, b):
	n = 0
	while not b.endswith(a):
		n += 1
		a = a[1:]
	return n + (len(b) - len(a))


def shift_left(a, b):
	(m, n, i) = (len(a), len(b), -1)
	while m > 0 and n > 0 and (a[i] == b[i]):
		(i, m, n) = (i - 1, m - 1, n - 1)
	return m + n


def shift_left(a, b):
	return next((len(a) + len(b) - 2 * len(b[i:]) for i in range(len(b)) if a.endswith(b[i:])), len(a) + len(b))