#include <bits/stdc++.h>
#pragma GCC optimize(3)
using namespace std;
int p, m;
int b[5010];
vector<int> v[5010];
vector<pair<int, int> > w;
map<pair<int, int>, int> mpp;
int ans = 1;
inline void dfs(int n) {
  b[n] = 1;
  for (int i = 0; i < v[n].size(); i++) {
    if (b[v[n][i]] == 1) {
      mpp[make_pair(n, v[n][i])] = 2;
      ans = 2;
    }
    if (b[v[n][i]] == 0) {
      mpp[make_pair(n, v[n][i])] = 1;
      dfs(v[n][i]);
    }
    if (b[v[n][i]] == 2) {
      mpp[make_pair(n, v[n][i])] = 1;
    }
  }
  b[n] = 2;
}
int main(int argc, char** argv) {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cin >> p >> m;
  for (int i = 0; i < m; i++) {
    int a, b;
    cin >> a >> b;
    v[a].push_back(b);
    w.push_back(make_pair(a, b));
  }
  for (int i = 1; i <= p; i++) {
    if (b[i] == 0) {
      dfs(i);
    }
  }
  cout << ans << endl;
  for (int i = 0; i < m; i++) {
    cout << mpp[w[i]] << " ";
  }
  return 0;
}
