ta1hia

from math import sqrt, pow

class ATaleOfThreeCities:

    AB = 1
    BC = 2
    CA = 3

    def __init__(self, min1=999, min2=999):
        self.min1 = min1

ta1hia

from collections import deque

def permutations(word):
    if len(word) == 1:
        return [word]

    perms = permutations(word[1:])
    c = word[0]
    res = []

ta1hia

from collections import deque

def permutations(word):
    if len(word) == 1:
        return [word]

    perms = permutations(word[1:])
    c = word[0]
    res = []

ta1hia

class BadNeighbours:

    def maxDonations(self, donations):
        L = len(donations)
        if L < 3:
            return max(donations)

        # memo1[L-2] will have maximum value of donations which
        # *may* include the first neighbour (therefore cannot include

ta1hia

class AvoidRoads:

    def badDict(self, bad):
        bd = {}
        for b in bad:
            bd[b] = True
        return bd

    def numWays(self, width, height, bad):

ta1hia

class State:

    def __init__(self, longest_sequence, next_diff):
        """ next_diff = 1 means the next expected difference
        in the zigzag sequence is positive
        next_diff = 0 means the next expected difference
        in the zigzag sequence is negative """
        self.longest = longest_sequence
        self.next_diff = next_diff

ta1hia

from collections import deque

class Square:
    def __init__(self, col, row, prev=None, moves=9999):
        self.col = col
        self.row = row
        self.prev = prev
        self.moves = moves

    def set_moves(self, moves):

ta1hia

class Vertex:
    def __init__(self, word, dist=9999):
        self.word = word
        self.dist = dist

def gen_all_neighbours(v, forbidden):
    """ Generate all neighbours for a vertex, i.e. all
        words that are one letter off. Uses ascii values and
        excludes any words in list(forbidden).
    """

ta1hia

def swap(S, i1, i2):
	l = list(S)
	l[i1], l[i2] = l[i2], l[i1]
	S = ''.join(l)
	return S

def prependBs(S, N):
    nBs = N - len(S)
    return "B"*nBs + S

ta1hia

# you can write to stdout for debugging purposes, e.g.
# print "this is a debug message"

def solution(A):
    # write your code in Python 2.7
    L = len(A)
    n = 0
    
    if L == 1:
        return 0