import sys,re
for k,s in re.findall('(\d+)\n([a-z, ]+)\n',open(sys.argv[1]).read()):
 k=map(int,k+k[::-1])
 b,i="",0
 for c in s:
    if c>' ':b+=chr((ord(c)-71-k[i])%26+97);i=(i+1)%len(k)
    else:b+=c
 print b