def trans(s,t):
result=[]
temp =[ s[i:i+len(t)]for i inrange(0,length,len(t))]for item in temp:
newItem=''for i in t:
newItem = newItem + item[i-1]
result.append(newItem)return''.join(result)
f =open('a.txt','r')
s = f.read()
length =len(s)
f.close()print(s+'\n')
b =trans(s,(2,1,4,3))
f =open('b.txt','w')
f.write(b)
f.close()print(b+'\n')
