n,m = map(int,input().split())
goods_dic = {}
count = n
c = 0
def search(goods):
    if goods_dic[goods]==False:
        return False
    elif goods_dic[goods]==[]:
        return True
    else:
        tmp = goods_dic[goods][:]
        goods_dic[goods] = False
        for i in tmp:
            if not search(i):
                global count
                count -= 1
                return False
        else:
            goods_dic[goods]=[]
            return True

for i in range(1,n+1):
    goods_dic[i] = []

for i in range(m):
    tmp1 = list(map(int,input().split()))
    tmp2 = list(map(int,input().split()))
    goods_dic[tmp1[0]] = tmp2

for i in range(1,n+1):
    search(i)

print(count)