# No.18 うーさー暗号

s = input()

sList = list(s)
aList = []
length = len(sList)

for c in range(length):
    sf = (c + 1) % 26
    o = ord(sList[c]) - sf
    if o < 65:
        o = o + 26
    
    aList.append(chr(o))

print("".join(aList))