#!/usr/bin/env python3

import pprint
import sys

input_file = sys.argv[1]

with open(input_file) as fd:
    lines = [line.rstrip() for line in fd.readlines()]

height = len(lines)
width = len(lines[0])

vec = tuple[int, int]

directions = [
    (-1, 0),  # ^ North
    (0, 1),  # > East
    (1, 0),  # v South
    (0, -1),  # < West
]

directions_keys = ("^", ">", "v", "<")

min_scores: list[list[list[None | int]]] = list()
for _ in range(height):
    line: list[list[None | int]] = list()
    for _ in range(width):
        cell: list[None | int] = [None] * len(directions)
        line.append(cell)
    min_scores.append(line)

start = height - 2, 1


def walk(pos: vec, dir: int, score: int, depth: int = 0) -> int | None:
    i, j = pos
    char = lines[i][j]

    if depth > 1000:
        return None

    # print("-" * depth, 28, pos, char, directions_keys[dir], score)
    if char == "E":
        return score
    elif char == "#":
        return None

    min_score = min_scores[i][j][dir]
    for d, min_score in enumerate(min_scores[i][j]):
        if min_score is None:
            continue
        if d == dir:
            if score >= min_score:
                return None
        else:
            if score >= min_score + 1000:
                return None
    min_scores[i][j][dir] = score

    mscore = None
    for ndir, direction in enumerate(directions):
        ii, jj = i + direction[0], j + direction[1]
        price = 1 if dir == ndir else 1001
        nscore = walk((ii, jj), ndir, score + price, depth + 1)
        if nscore is None:
            continue
        if mscore is None or nscore < mscore:
            mscore = nscore
    return mscore


sys.setrecursionlimit(3000)
tot_score = walk(start, 1, 0)

# Viz
for i in range(height):
    cline = ""
    for j in range(width):
        char = lines[i][j]
        min_score = None
        for d in range(len(directions)):
            score = min_scores[i][j][d]
            if score is None:
                continue
            if min_score is None or score < min_score:
                char = directions_keys[d]
                min_score = score
        cline += char
    print(cline)
print()

print(tot_score)