#include <fstream>
#include <cmath>
#include <vector>
#include <algorithm>
#include <list>

using namespace std;

ifstream cin("input.txt");
ofstream cout("output.txt");
//ifstream cin(" firesafe.in");
//ofstream cout("firesafe.out");


vector < list <int> > g, gt, scc;
vector < bool > used;
vector < vector < int > > c;
vector < int > order, res, color;
int n, m;

void init(){
	used.resize(n);
	g.resize(n);
	gt.resize(n);
	c.resize(n);
	color.resize(n);
	for (int i = 0; i < n; i++)
		c[i].resize(n);
}

void dfs(int v){
	int j;
	list < int >:: iterator it;
	used[v] = true;
	for (it = g[v].begin(); it != g[v].end(); it++){
		j = *it;
		if (!used[j])
			dfs(j);
	}
	order.push_back(v);
}

void dfs1(int v){
	int j;
	list < int >:: iterator it;
	list < int >:: iterator jt;
	used[v] = true;
	scc[scc.size() - 1].push_back(v);
	for (it = gt[v].begin(); it != gt[v].end(); it++){
		j = *it;
		if (!used[j])
			dfs1(j);
	}
}

void bingo(int v){
	res.push_back(v);
}

void dfs2(int v){
	used[v] = true;
	bool children = false;
	for (int i = 0; i < scc.size(); i++)
		if (!used[i] && c[scc[v].front()][scc[i].front()] == 1){
			dfs2(i);
			children = true;
		}
	if (!children)
		bingo(scc[v].front());
}

int main() {
	cin >> n >> m;
	init();
	for (int i = 0; i < m; i++){
		int v, u;
		cin >> v >> u;
		g[v - 1].push_back(u - 1);
		gt[u - 1].push_back(v - 1);
	}
	for (int i = 0; i < n; i++)
		if (!used[i])
			dfs(i);
	used.assign(n, false);
	for (int i = n - 1; i >= 0; i--)
		if (!used[order[i]]){
			list < int >:: iterator it;
			list < int >:: iterator jt;
			scc.resize(scc.size() + 1);
			dfs1(order[i]);
			for (it = scc[scc.size() - 1].begin(); it != scc[scc.size() - 1].end(); it++)
				color[*it] = scc.size();
		}
	cout << scc.size() << endl;
	for (int i = 0; i< n; i++)
		cout << color[i] << " ";
	return 0;
}