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int cnt, scc_num, scc[MAXN], in[MAXN], low[MAXN];
stack<int> s;
bitset<MAXN> ins;

void tarjan(int u) {
	low[u] = in[u] = cnt++;
	s.push(u);
	ins[u] = 1;
	for (int v : G[u]) {
		if (in[v] == -1) tarjan(v), low[u] = min(low[u], low[v]);
		else if (ins[v]) low[u] = min(low[u], in[v]);
	}
	if (low[u] == in[u]) {
		while (1) {
			int x = s.top(); s.pop();
			scc[x] = scc_num, ins[x] = 0;
			if (x == u) break;
		}
		++scc_num;
	}
}


memset(scc, -1, sizeof scc), memset(in, -1, sizeof in);
for (int u = 1; u <= N; ++u) if (scc[u] == -1) tarjan(u);