aoc

import sys
import re
from copy import deepcopy
from math import gcd
from collections import defaultdict, Counter, deque

D = open(sys.argv[1]).read().strip()
L = D.split("\n")

G = [[c for c in row] for row in L]
R = len(G)
C = len(G[0])

for r in range(R):
    for c in range(C):
        if G[r][c] == "S":
            sr, sc = r, c
            up_valid = G[r - 1][c] in ["|", "7", "F"]
            right_valid = G[r][c + 1] in ["-", "7", "J"]
            down_valid = G[r + 1][c] in ["|", "L", "J"]
            left_valid = G[r][c - 1] in ["-", "L", "F"]
            assert sum([up_valid, right_valid, down_valid, left_valid]) == 2
            if up_valid and down_valid:
                G[r][c] = "|"
                sd = 0
            elif up_valid and right_valid:
                G[r][c] = "L"
                sd = 0
            elif up_valid and left_valid:
                G[r][c] = "J"
                sd = 0
            elif down_valid and right_valid:
                G[r][c] = "F"
                sd = 2
            elif down_valid and left_valid:
                G[r][c] = "7"
                sd = 2
            elif left_valid and right_valid:
                G[r][c] = "-"
                sd = 1
            else:
                assert False

# up right down left
DR = [-1, 0, 1, 0]
DC = [0, 1, 0, -1]
r = sr
c = sc
d = sd
dist = 0
while True:
    dist += 1
    r += DR[d]
    c += DC[d]
    if G[r][c] == "L":
        if d not in [2, 3]:
            break
        elif d == 2:
            d = 1
        else:
            d = 0
    if G[r][c] == "J":
        if d not in [1, 2]:
            break
        elif d == 1:
            d = 0
        else:
            d = 3
    if G[r][c] == "7":
        # up right dswn left
        if d not in [0, 1]:
            break
        elif d == 0:
            d = 3
        else:
            d = 2
    if G[r][c] == "F":
        if d not in [0, 3]:
            break
        elif d == 0:
            d = 1
        else:
            d = 2
    assert G[r][c] != "."
    if (r, c) == (sr, sc):
        print(dist // 2)
        break

R2 = 3 * R
C2 = 3 * C
G2 = [["." for _ in range(C2)] for _ in range(R2)]
for r in range(R):
    for c in range(C):
        if G[r][c] == "|":
            G2[3 * r + 0][3 * c + 1] = "x"
            G2[3 * r + 1][3 * c + 1] = "x"
            G2[3 * r + 2][3 * c + 1] = "x"
        elif G[r][c] == "-":
            G2[3 * r + 1][3 * c + 0] = "x"
            G2[3 * r + 1][3 * c + 1] = "x"
            G2[3 * r + 1][3 * c + 2] = "x"
        elif G[r][c] == "7":
            G2[3 * r + 1][3 * c + 0] = "x"
            G2[3 * r + 1][3 * c + 1] = "x"
            G2[3 * r + 2][3 * c + 1] = "x"
        elif G[r][c] == "F":
            G2[3 * r + 2][3 * c + 1] = "x"
            G2[3 * r + 1][3 * c + 1] = "x"
            G2[3 * r + 1][3 * c + 2] = "x"
        elif G[r][c] == "J":
            G2[3 * r + 1][3 * c + 0] = "x"
            G2[3 * r + 1][3 * c + 1] = "x"
            G2[3 * r + 0][3 * c + 1] = "x"
        elif G[r][c] == "L":
            G2[3 * r + 0][3 * c + 1] = "x"
            G2[3 * r + 1][3 * c + 1] = "x"
            G2[3 * r + 1][3 * c + 2] = "x"
        elif G[r][c] == ".":
            pass
        else:
            assert False, G[r][c]
for row in G2:
    # print(''.join(row))
    pass

Q = deque()
SEEN = set()
for r in range(R2):
    Q.append((r, 0))
    Q.append((r, C2 - 1))
for c in range(C2):
    Q.append((0, c))
    Q.append((R2 - 1, c))
while Q:
    r, c = Q.popleft()
    if (r, c) in SEEN:
        continue
    if not (0 <= r < R2 and 0 <= c < C2):
        continue
    SEEN.add((r, c))
    if G2[r][c] == "x":
        continue
    for d in range(4):
        Q.append((r + DR[d], c + DC[d]))
ans = 0
for r in range(R):
    for c in range(C):
        seen = False
        for rr in [0, 1, 2]:
            for cc in [0, 1, 2]:
                if (3 * r + rr, 3 * c + cc) in SEEN:
                    seen = True
        if not seen:
            ans += 1
print(ans)