instruction, key, string = input().split()

def char_to_num(c):
    return(ord(c)-ord('a'))
def num_to_char(n):
    return(chr(n+ord('a')))


out = [' ']*len(string)
if(instruction=="encode"):
    for i in range(0,len(string)):
        out[i] = num_to_char((char_to_num(string[i])+char_to_num(key[i%len(key)]))%26)
elif(instruction=="decode"):
    for i in range(0,len(string)):
        out[i] = num_to_char((char_to_num(string[i])-char_to_num(key[i%len(key)]))%26)

print("".join(out))