# union find
class UnionFind
  def initialize(n)
    @parents = Array.new(n) { |i| i }
    @ranks = Array.new(n) { 0 }
  end

  def root(x)
    if @parents[x] == x
      x
    else
      @parents[x] = root(@parents[x])
    end
  end

  def unite(x, y)
    root_x = root(x)
    root_y = root(y)
    return if root_x == root_y

    if @ranks[root_x] < @ranks[root_y]
      @parents[root_x] = root_y
    else
      @parents[root_y] = root_x
      @ranks[root_x] += 1 if @ranks[root_x] == @ranks[root_y]
    end
  end

  def same?(x, y)
    root(x) == root(y)
  end
end

n, m = gets.split.map(&:to_i)
u = UnionFind.new(n+1)
xyz = []
h = Hash.new([])
m.times do
  ary = gets.split.map(&:to_i)
  xyz.push ary
  h[ary[0]] += [[ary[1], ary[2]]]
  h[ary[1]] += [[ary[0], ary[2]]]
  u.unite(ary[0], ary[1]) unless u.same?(ary[0], ary[1])
end

count = n - h.size

roots = Hash.new(false)

h.each do |k, v|
  roots[u.root(k)] = true
end

count += roots.size
puts count
