#!/usr/bin/env python
# -*- coding: utf-8 -*-

# No.18 うーさー暗号
def main():
    s = input()
    ans = ''
    for idx, c in enumerate(s):
        # single byte code A:65, B:66, ... ,Y:89,Z:90
        shift_size = ((idx + 1) % 26)
        if (ord(c) - ord('A') - shift_size) >= 0:
            ans += chr(ord(c) - shift_size)
        else:
            ans += chr(ord('Z') + (ord(c) - ord('A') - shift_size) + 1)

    print(ans)


if __name__ == '__main__':
    main()