```
#!/usr/bin/env python2
from random import shuffle
import itertools
import sys

W = 7
perm = range(W)
ps = list(itertools.permutations(perm))
msg = open("output").read() # L{NTP#AGLCSF.#OAR4A#STOL11__}PYCCTO1N#RS.S
dmsg = msg

if len(msg) % 14:
print "wrong length"
sys.exit(1)

def dex0r():
global W, perm, msg
for i in xrange(100):
# 1) reorder every 7 characters according to permutaion
res = ""
for j in xrange(0, len(msg), W):
for k in xrange(W):
res += msg[j:j+W][perm[k]]
msg = res

# 2) move last character to beginning
msg = msg[-1:] + msg[:-1]

# 3) combine even and odd chars back
evens = msg[0:int(len(msg)/2)]
odds = msg[int(len(msg)/2):len(msg)]
msg = ''.join(a+b for a,b in zip(evens, odds))

# 4) move last letter to beginning
msg = msg[-1:] + msg[:-1]

a=0
while a < len(ps):
perm = ps[a]
dex0r()
if "FLAG" in msg:
print msg
msg = dmsg
a += 1
```