CHR_SIZE = 26

S = list(input())
for i in range(len(S)):
	pos = ord(S[i]) - ord('A')
	pos -= (i+1)
	pos %= CHR_SIZE
	if(pos < 0):
		pos += CHR_SIZE
	x = chr(pos + ord('A'))
	S[i] = x
print(*S , sep="")