소프티어

풀이 영상 보고 풀었는데 어디가 문제인가요?

import sys
input = sys.stdin.readline
sys.setrecursionlimit(10**9)

def dfs(s,g,visit):
    if visit[s]==1:
        return
    visit[s]=1
    for x in g[s]:
        dfs(x,g,visit)

    

n,m = map(int,input().split())
graph=[[] for _ in range(n+1)]
graph_r=[[] for _ in range(n+1)]
for _ in range(m):
    a,b=map(int,input().split())
    graph[a].append(b)
    graph_r[b].append(a)
s,e = map(int,input().split())

s_in = [0]*(n+1)
dfs(s,graph_r,s_in)

s_out = [0]*(n+1)
s_out[e]=1
dfs(s,graph,s_out)

e_in = [0]*(n+1)
dfs(e,graph_r,e_in)

e_out = [0]*(n+1)
e_out[s]=1
dfs(e,graph,e_out)

ans=0
for i in range(n+1):
    if s_in[i] and s_out[i] and e_in[i] and e_out[i]:
        ans+=1
print(ans-2)