#include <iostream>
#include <vector>
#include <queue>
using namespace std;

struct node
{
	int num, i, o;
	vector <int> f;
	node() {}
	node(int num1, int i1, int o1)
	{
		num = num1;
		i = i1;
		o = o1;
	}
};

int ans[1000001];

int main()
{
	int n, m, i, j, a, b;
	vector <node> v;
	queue <node> q;
	cin >> n >> m;
	for (i = 0; i <= n; ++i)
		v.push_back(node(i, 0, 0));
	for (i = 1; i <= m; ++i)
	{
		cin >> a >> b;
		v[a].o++;
		v[a].f.push_back(b);
		v[b].i++;
	}
	for (i = 1; i <= n; ++i)
	{
		if (!v[i].i)
		{
			q.push(v[i]);
			ans[i] = 1;
		}
		cout << i << ": ";
		for (j = 0; j < v[i].f.size(); ++j)
			cout << v[i].f[j] << ' ';
		cout << ' ' << v[i].i << ' ' << v[i].o << endl;
	}
	while (!q.empty())
	{
		cout << q.front().num << ' ';
		cout << q.front().o << endl;
		for (i = 0; i < q.front().o; ++i)
		{
			v[q.front().f[i]].i--;
			if (!v[q.front().f[i]].i)
			{
				q.push(node(q.front().f[i], v[q.front().f[i]].i - 1, v[q.front().f[i]].o));
				ans[q.front().f[i]] += ans[q.front().num];
			}
		}
		q.pop();
	}
	for (i = 1; i <= n; ++i)
	{
		if (!v[i].o)
			ans[0] += ans[i];
	}
	cout << ans[0];
	return 0;
}