import sys
import time

key = 4
word = "Send.more.reinforcements.for.the.monkey-catching.operation"

temp_word = str(word)
dist=2*(key-1)

for x in range(len(word)%key):
    temp_word = temp_word + '_'

fpos = key-1
cypher = ''

for i in reversed(range(key)):
    for j in range((len(temp_word))/dist):

        if i == key -1:
            cypher = cypher +  temp_word[fpos + j*dist]
        elif i==0:
            cypher = cypher +  temp_word[fpos + j*dist - (key -1)]
        else:
            cypher = cypher +  temp_word[fpos + j*dist - (key - i -1)]
            cypher = cypher +  temp_word[fpos + j*dist + (key - i -1)]

        sys.stdout.write("\r" + cypher)
        sys.stdout.flush()
        time.sleep(0.5)