#include <iostream>
#include <vector>
#include <algorithm>
#define pb push_back
#define ll long long
using namespace std;

vector<vector<int>> g, tg;
vector<int> tsort;
vector<int> used;
vector<int> comps;
int k = 0;

void t_dfs(int v) {
    ++k;
    used[v] = 1;
    for (int s : g[v]) {
        if (!used[s]) t_dfs(s);
    }
    tsort.pb(v);
}

void dfs(int v, int col) {
    used[v] = 1;
    if (comps[v] == -1) {
        comps[v] = col;
    }
    for (int s : tg[v]) {
        if (!used[s]) dfs(s, col);
    }
}

int main() {
    //freopen("input.txt", "r", stdin);
    int n, m;
    cin >> n >> m;
    for (int i = 0; i < n; ++i) {
        g.pb({});
        tg.pb({});
        used.pb(0);
    }
    for (int i = 0; i < m; ++i) {
        int a, b;
        cin >> a >> b;
        --a;
        --b;
        g[a].pb(b);
        tg[b].pb(a);
    }

    while (k < n) {
        for (int i = 0; i < n; ++i) {
            if (!used[i]) t_dfs(i);
        }
    }
    /*for (int i = 0; i < n; ++i) cout << tsort[i] << " ";
    cout << "\n";*/

    for (int i = 0; i < n; ++i) {
        comps.pb(-1);
        used[i] = 0;
    }

    int t = 0;
    for (int i = n - 1; i >= 0; --i) {
        if (comps[tsort[i]] == -1) {
            dfs(tsort[i], t);
            ++t;
        }
    }

    cout << t << "\n";
    for (int i = 0; i < n; ++i) {
        cout << comps[i] + 1 << " ";
    }
    return 0;
}