import sys
def solve():
    s = sys.stdin.readline().strip()
    out = []
    for i, ch in enumerate(s):
        shift = (i + 1) % 26
        c = ord(ch) - 65 - shift
        if c < 0:
            c += 26
        out.append(chr(c + 65))
    sys.stdout.write(''.join(out) + '\n')

if __name__ == '__main__':
    solve()