import numpy as np
import numpy.linalg as LA

N, M = map(int, input().split())
A = np.zeros((N, N), dtype=int)
for i in range(0, M):
    a, b, c = map(int, input().split())
    A[a - 1][b - 1] = c
    A[b - 1][a - 1] = c
for i in range(0, N):
    A[i][i] = -sum(A[i])
eigenvalues, _ = LA.eig(A)
ans = 0
for eigenvalues in eigenvalues:
    if abs(eigenvalues) < 1e-9:
        ans += 1

print(ans)