n, m=gets.split.map(&:to_i)
g=Array.new(n){[]}
deg=Array.new(n){0}
m.times do
  gi, ri=gets.split.map(&:to_i)
  h=gets.split.map(&:to_i)
  deg[gi-1]+=ri
  h.each{|v| g[v-1].push(gi-1)}
end

q=[]
n.times do |i|
  q.push(i) if deg[i]==0
end
tot=0
while q.size>0
  u=q.shift
  tot+=1
  g[u].each do |v|
    next if deg[v]==0
    q.push(v) if (deg[v]-=1)==0
  end
end

puts tot