# solve.py
# Reverse the shifting to recover the original plaintext

def unshift_letter(letter, shift):
    start = ord('A') if letter.isupper() else ord('a')
    return chr(start + (ord(letter) - start - shift) % 26)


def solve(encoded):
    out = ""
    i = 25  # starting shift

    for c in encoded:
        if c in ['{', '}', '_']:
            out += c
            continue

        out += unshift_letter(c, i)
        i -= 1

    return out


if __name__ == "__main__":
    a = 'BRC{ivex_uruhoe_otzqmy_mwidv_bgzgk}'
    print(solve(a))