#include #include using namespace std; #define rep(i,n) for(long long i = 0; i < (long long)(n); i++) #define repi(i,a,b) for(long long i = (long long)(a); i < (long long)(b); i++) #define pb push_back #define all(x) (x).begin(), (x).end() #define fi first #define se second #define mt make_tuple #define mp make_pair #define ZERO(a) memset(a,0,sizeof(a)) template bool chmin(T1 &a, T2 b) { return b < a && (a = b, true); } template bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); } #define exists find_if #define forall all_of using ll = long long; using vll = vector; using vvll = vector; using P = pair; using ld = long double; using vld = vector; using vi = vector; using vvi = vector; vll conv(vi& v) { vll r(v.size()); rep(i, v.size()) r[i] = v[i]; return r; } using Pos = complex; template ostream &operator<<(ostream &o, const pair &v) { o << "(" << v.first << ", " << v.second << ")"; return o; } template struct seq{}; template struct gen_seq : gen_seq{}; template struct gen_seq<0, Is...> : seq{}; template void print_tuple(basic_ostream& os, Tuple const& t, seq){ using s = int[]; (void)s{0, (void(os << (Is == 0? "" : ", ") << get(t)), 0)...}; } template auto operator<<(basic_ostream& os, tuple const& t) -> basic_ostream& { os << "("; print_tuple(os, t, gen_seq()); return os << ")"; } ostream &operator<<(ostream &o, const vvll &v) { rep(i, v.size()) { rep(j, v[i].size()) o << v[i][j] << " "; o << endl; } return o; } template ostream &operator<<(ostream &o, const vector &v) { o << '['; rep(i, v.size()) o << v[i] << (i != v.size()-1 ? ", " : ""); o << "]"; return o; } template ostream &operator<<(ostream &o, const set &m) { o << '['; for (auto it = m.begin(); it != m.end(); it++) o << *it << (next(it) != m.end() ? ", " : ""); o << "]"; return o; } template ostream &operator<<(ostream &o, const unordered_set &m) { o << '['; for (auto it = m.begin(); it != m.end(); it++) o << *it << (next(it) != m.end() ? ", " : ""); o << "]"; return o; } template ostream &operator<<(ostream &o, const map &m) { o << '['; for (auto it = m.begin(); it != m.end(); it++) o << *it << (next(it) != m.end() ? ", " : ""); o << "]"; return o; } template ostream &operator<<(ostream &o, const unordered_map &m) { o << '['; for (auto it = m.begin(); it != m.end(); it++) o << *it; o << "]"; return o; } vector range(const int x, const int y) { vector v(y - x + 1); iota(v.begin(), v.end(), x); return v; } template istream& operator>>(istream& i, vector& o) { rep(j, o.size()) i >> o[j]; return i;} string bits_to_string(ll input, ll n=64) { string s; rep(i, n) s += '0' + !!(input & (1ll << i)); reverse(all(s)); return s; } template ostream &operator<<(ostream &o, const priority_queue &v) { auto tmp = v; while (tmp.size()) { auto x = tmp.top(); tmp.pop(); o << x << " ";} o << endl; return o; } template unordered_map counter(vector vec){unordered_map ret; for (auto&& x : vec) ret[x]++; return ret;}; string substr(string s, P x) {return s.substr(x.fi, x.se - x.fi); } struct ci : public iterator { ll n; ci(const ll n) : n(n) { } bool operator==(const ci& x) { return n == x.n; } bool operator!=(const ci& x) { return !(*this == x); } ci &operator++() { n++; return *this; } ll operator*() const { return n; } }; size_t random_seed; namespace std { using argument_type = P; template<> struct hash { size_t operator()(argument_type const& x) const { size_t seed = random_seed; seed ^= hash{}(x.fi); seed ^= (hash{}(x.se) << 1); return seed; } }; }; // hash for various class namespace myhash{ const int Bsizes[]={3,9,13,17,21,25,29,33,37,41,45,49,53,57,61,65,69,73,77,81}; const int xor_nums[]={0x100007d1,0x5ff049c9,0x14560859,0x07087fef,0x3e277d49,0x4dba1f17,0x709c5988,0x05904258,0x1aa71872,0x238819b3,0x7b002bb7,0x1cf91302,0x0012290a,0x1083576b,0x76473e49,0x3d86295b,0x20536814,0x08634f4d,0x115405e8,0x0e6359f2}; const int hash_key=xor_nums[rand()%20]; const int mod_key=xor_nums[rand()%20]; template struct myhash{ std::size_t operator()(const T& val) const { return (hash{}(val)%mod_key)^hash_key; } }; }; template class uset:public std::unordered_set> { using SET=std::unordered_set>; public: uset():SET(){SET::rehash(myhash::Bsizes[rand()%20]);} }; uint32_t randxor() { static uint32_t x=1+(uint32_t)random_seed,y=362436069,z=521288629,w=88675123; uint32_t t; t=(x^(x<<11));x=y;y=z;z=w; return( w=(w^(w>>19))^(t^(t>>8)) ); } struct timeval start; double sec() { struct timeval tv; gettimeofday(&tv, NULL); return (tv.tv_sec - start.tv_sec) + (tv.tv_usec - start.tv_usec) * 1e-6; } struct init_{init_(){ gettimeofday(&start, NULL); ios::sync_with_stdio(false); cin.tie(0); struct timeval myTime; struct tm *time_st; gettimeofday(&myTime, NULL); time_st = localtime(&myTime.tv_sec); srand(myTime.tv_usec); random_seed = RAND_MAX / 2 + rand() / 2; }} init__; #define rand randxor static const long long mo = 1e9+7; #define ldout fixed << setprecision(40) /***********************/ // 共通部分 /***********************/ #define REP(i,n) for(int i=0;i<(int)n;++i) #define FOR(i,c) for(__typeof((c).begin())i=(c).begin();i!=(c).end();++i) #define ALL(c) (c).begin(), (c).end() typedef long long Weight; const Weight INF = 1e18; const Weight EPS = 0; // 浮動小数点なら1e-14 struct Edge { ll src, dst; Weight weight; // 最小費用流ではcostの役割 ll cap; ll rev; // 残余グラフの対応用 bool rev_flag = false; // revなら1 Edge(int src = 0, int dst = 0, int weight = 0, Weight cap = 1): src(src), dst(dst), weight(weight), cap(cap){ } }; bool operator < (const Edge &e, const Edge &f) { return e.weight != f.weight ? e.weight > f.weight : // !!INVERSE!! e.src != f.src ? e.src < f.src : e.dst < f.dst; } typedef vector Edges; typedef vector Graph; typedef vector Array; typedef vector Matrix; // 最大流と最小費用流の有向 // 無向は自分でひっくり返して追加して下さい void addDirected(Graph& g, ll src, ll dst, Weight weight = 0, ll cap = 0) { assert(src < g.size() && src >= 0 && dst < g.size() && dst >= 0); g[src].push_back(Edge(src, dst, weight, cap)); } vector names; unordered_map name_server; void clearNameServer(void) { names.clear(); name_server.clear(); } int constructNameServer(vector& names_) { names = names_; for (int i = 0; i < names.size(); i++) { name_server[names[i]] = i; } return name_server.size(); } void addDirected(Graph& g, string src, string dst, Weight weight = 0, ll cap = 0) { if (!name_server.count(src)) { cerr << "No such node : " << src << endl; exit(1); } if (!name_server.count(dst)) { cerr << "No such node : " << dst << endl; exit(1); } addDirected(g, name_server[src], name_server[dst], weight, cap); } void addUndirected(Graph& g, ll src, ll dst, Weight weight = 0, ll cap = 0) { addDirected(g, src, dst, weight, cap); addDirected(g, dst, src, weight, cap); } void transformFromMatrixToGraph(Graph& g, Matrix& m) { ll n = m.size(); g.resize(n); rep(i, n) rep(j, n) if (m[i][j] != INF) { addDirected(g, i, j, m[i][j]); } } void printGraph(Graph& g) { rep(i, g.size()) { if (!g[i].size()) continue; rep(j, g[i].size()) cout << "(" << i << ", " << g[i][j].dst << "), "; cout << endl; } } void printGraphCap(Graph& g) { rep(i, g.size()) { if (!g[i].size()) continue; rep(j, g[i].size()) cout << "(" << i << ", " << g[i][j].dst << " : " << g[i][j].cap << ", " << (g[i][j].rev_flag ? "rev" : "for") << "), "; cout << endl; } } // mode // // 0 : デフォルト。辺だけ表示 // 1 : 重みweightだけ表示 // 2 : フロー用。weight, capを表示。 void vizGraph(Graph& g, int mode = 0, string filename = "out.png") { ofstream ofs("./out.dot"); ofs << "digraph graph_name {" << endl; rep(i, g.size()) { if (!g[i].size()) continue; rep(j, g[i].size()) { if (name_server.size()) { ofs << " " << names[i] << " -> " << names[g[i][j].dst]; } else { ofs << " " << i << " -> " << g[i][j].dst; } if (mode == 1) { ofs << " [ label = \"" << g[i][j].weight << "\"];"; } else if (mode == 2) { ofs << " [ label = \"" << g[i][j].weight << "/" << (g[i][j].cap == INF ? "inf" : to_string(g[i][j].cap)) << "\"];"; } ofs << endl; } } ofs << "}" << endl; ofs.close(); system(((string)"dot -T png out.dot >" + filename).c_str()); } // 強連結分解 // O(V+E) // const Graph& g 有向グラフ // vector< vector >& scc グラフの強連結成分 void visitStronglyConnectedComponents(const Graph &g, ll v, vector< vector >& scc, stack &S, vector &inS, vector &low, vector &num, ll& time) { low[v] = num[v] = ++time; S.push(v); inS[v] = true; FOR(e, g[v]) { ll w = e->dst; if (num[w] == 0) { visitStronglyConnectedComponents(g, w, scc, S, inS, low, num, time); low[v] = min(low[v], low[w]); } else if (inS[w]) low[v] = min(low[v], num[w]); } if (low[v] == num[v]) { scc.push_back(vector()); while (1) { ll w = S.top(); S.pop(); inS[w] = false; scc.back().push_back(w); if (v == w) break; } } } void stronglyConnectedComponents(const Graph& g, vector< vector >& scc) { const ll n = g.size(); vector num(n), low(n); stack S; vector inS(n); ll time = 0; rep(u, n) if (num[u] == 0) visitStronglyConnectedComponents(g, u, scc, S, inS, low, num, time); } int main(void) { ll n, m; cin >> n >> m; Graph g = Graph(n); rep(i, m) { ll x, r; cin >> x >> r; x--; rep(i, r) { ll u; cin >> u; u--; addDirected(g, u, x); } } vizGraph(g); vector> scc; stronglyConnectedComponents(g, scc); vll colored(n); rep(i, scc.size()) if (scc[i].size() != 1) for (auto x : scc[i]) colored[x] = 1; function dfs = [&](ll u) { for (auto x : g[u]) if (!colored[x.dst]) colored[x.dst] = 1, dfs(x.dst); }; rep(i, n) if (colored[i]) dfs(i); ll ret = 0; rep(i, n) ret += colored[i] == 0; cout << ret << endl; return 0; }