#include <bits/stdc++.h>
using namespace std;
int ans = 1;
int e[5005] = {0};
void dfs(int node, vector<vector<pair<int, int>>> &g, vector<int> &vis) {
  vis[node] = 1;
  for (auto v : g[node]) {
    if (vis[v.first] == 0) {
      dfs(v.first, g, vis);
    }
    if (vis[v.first] == 1) {
      ans = 2;
      e[v.second] = 2;
    }
  }
  vis[node] = 2;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int n, m;
  cin >> n >> m;
  ans = 1;
  int u, v;
  vector<vector<pair<int, int>>> g(n);
  for (int i = 0; i < m; i++) {
    cin >> u >> v;
    g[u - 1].push_back({v - 1, i});
    e[i] = 1;
  }
  vector<int> vis(n);
  for (int i = 0; i < n; i++) vis[i] = 0;
  for (int i = 0; i < n; i++)
    if (vis[i] == 0) dfs(i, g, vis);
  cout << ans << endl;
  for (int i = 0; i < m; i++) {
    cout << e[i] << " ";
  }
  cout << endl;
  return 0;
}
