N, M = gets.split.map(&:to_i)
E = Hash.new { |h, k| h[k] = [] }
C = Hash.new { |h, k| h[k] = Hash.new }

M.times do
  a, b = gets.split.map(&:to_i)
  y = gets.to_i

  E[a] << b
  E[b] << a

  if C[a][b] && C[a][b] != y
    puts -1
    exit
  end

  C[a][b] = C[b][a] = y
end

ans = Array.new(N + 1, -1)
visited = Array.new(N + 1, false)

1.upto(N) do |i|
  next if visited[i]

  queue = []
  queue << [i, 0]

  until queue.empty?
    u, x = queue.shift

    next if visited[u]
    visited[u] = true
    ans[u] = x

    E[u].each do |v|
      c = C[u][v]
      nc = c ^ x

      if ans[v] != -1 && ans[v] != nc
        puts -1
        exit
      end

      queue << [v, nc]
    end
  end
end

puts ans[1..-1]