第五题网红，暴力解了，为什么一直50%，而且不是超时和数组越界的问题，不解
import sys
import queue
'''
input:3
3
1 2 2 1 2 3
output:1
'''
if __name__ == '__main__':
N = int(sys.stdin.readline().strip())
M = int(sys.stdin.readline().strip())
line = sys.stdin.readline().strip().split()
relationshape = []
Nmatrix = [[0 for i in range(N)] for j in range(N)]
for i in range(M):
tmp = (int(line[2*i]),int(line[2*i+1]))
relationshape.append(tmp)
for i in relationshape:
tmpi = i[0]-1
tmpj = i[1]-1
Nmatrix[tmpi][tmpj] = 1
for i in range(N):
if(Nmatrix[i][tmpi]==1):
Nmatrix[i][tmpj]=1
# print(Nmatrix)
result = 0
for i in range(N):
count = 0
for j in range(N):
if(Nmatrix[j][i]==1 and j!=i):
count+=1
if(count == N-1):
result += 1
print(result)
