Longest route

import sys
sys.setrecursionlimit(10**6)

def find_path(s, f, visited=None):
    global g, n

    path = [s]
    if s == f:
        paths[s] = path
        return path

    max_path = None
    res_path = None
    for w in g[s]:
        # print(w)
        if paths[w]:
            res_path = paths[w]
            if res_path and (not max_path or len(res_path) > len(max_path)):
                max_path = res_path
        else:
            res_path = find_path(w, f)
            if res_path and (not max_path or len(res_path) > len(max_path)):
                max_path = res_path

    path.extend(max_path)
    paths[s] = path
    # print('mp', max_path, res_path)
    return path


n, m = map(int, input().split())
g = [[] for _ in range(n)]
for i in range(m):
    a, b = map(int, input().split())
    g[a - 1].append(b - 1)

paths = [[] for _ in range(n)]
# print(paths)
#
# print(g)
path = find_path(0, n - 1)
# print(paths)
print(len(path))
for i in range(len(path)):
    path[i] += 1
print(*path)

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 41, in <module>
    path =...

Test 4

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 41, in <module>
    path =...

Test 5

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 41, in <module>
    path =...

Test 6

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 41, in <module>
    path =...

Test 7

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 41, in <module>
    path =...

Test 8

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 41, in <module>
    path =...

Test 9

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 41, in <module>
    path =...

Test 10

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 41, in <module>
    path =...

Test 11

Verdict: ACCEPTED

Test 12

Verdict: TIME LIMIT EXCEEDED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 41, in <module>
    path =...

Test 15

Verdict: TIME LIMIT EXCEEDED

Test 16

Verdict: ACCEPTED

Test 17

Verdict: TIME LIMIT EXCEEDED

Test 18

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 41, in <module>
    path =...

Test 19

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 41, in <module>
    path =...

Test 20

Verdict: TIME LIMIT EXCEEDED

Test 21

Verdict: ACCEPTED