def conversion(a, b):
    c = ord(a)
    d = c - b
    if d <= 64:
        return chr(d + 26)
    else:
        return chr(d)
inp = input()
out = ""
for i in range(len(inp)):
    x = i + 1
    returns = conversion(inp[i], x)
    out += returns
print(out)