#include <bits/stdc++.h>
using namespace std;
int n, m, u, v, num_col = 1;
vector<int> adjList[5001];
vector<int> edges[5001];
bitset<5001> vis;
bitset<5001> act;
bitset<5001> col;
void dfs(int nd) {
  vis[nd] = 1;
  act[nd] = 1;
  for (int k = 0; k < adjList[nd].size(); k++) {
    int nd_b = adjList[nd][k];
    int edge_num = edges[nd][k];
    if (!vis[nd_b])
      dfs(nd_b);
    else if (act[nd_b]) {
      num_col = 2;
      col[edge_num] = 1;
    }
  }
  act[nd] = 0;
}
int main() {
  cin >> n >> m;
  for (int i = 0; i < m; i++) {
    cin >> u >> v;
    u--;
    v--;
    adjList[u].push_back(v);
    edges[u].push_back(i);
  }
  for (int i = 0; i < n; i++) {
    if (!vis[i]) dfs(i);
  }
  cout << num_col << endl;
  for (int i = 0; i < m; i++) {
    cout << (((int)col[i]) + 1) << (i < m - 1 ? " " : "");
  }
  cout << endl;
  return 0;
}
