s = input()

a = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
a_list = list(a)

encryption_list = []

for i in range(len(s)):
    for j in range(len(a_list)):
        if s[i] == a_list[j]:
            encryption_list.append(a_list[j - (i+1)%26])
encryption = ''.join(encryption_list)
print(encryption)