"""Alphabet board path — find moves on a 5x5+1 letter board.

Given a board where 'a'-'z' are laid out in rows of 5:

a b c d e

f g h i j

k l m n o

p q r s t

u v w x y

z

Return the sequence of moves (U/D/L/R/!) to spell a target word

starting from 'a'.

Inspired by PR #897 (chnttx).

"""

from __future__ import annotations

def alphabet_board_path(target: str) -> str:

"""Return move string to spell *target* on the alphabet board."""

moves: list[str] = []

row, col = 0, 0

for ch in target:

idx = ord(ch) - ord("a")

target_row, target_col = divmod(idx, 5)

# Move up/left before down/right to avoid going off-board at 'z'

if target_row < row:

moves.append("U" * (row - target_row))

if target_col < col:

moves.append("L" * (col - target_col))

if target_row > row:

moves.append("D" * (target_row - row))

if target_col > col:

moves.append("R" * (target_col - col))

moves.append("!")

row, col = target_row, target_col

return "".join(moves)