#include <bits/stdc++.h>
using namespace std;
template <class T>
istream &operator>>(istream &in, vector<T> &arr) {
  for (auto &x : arr) in >> x;
  return in;
}
long long n, m;
const long long N = 1e6 + 100;
vector<pair<long long, long long>> g[N];
long long col[N];
bool cyc;
long long res[N];
void dfs(long long r) {
  col[r] = 1;
  for (auto x : g[r]) {
    long long to = x.first, ind = x.second;
    if (col[to] == 0) {
      res[ind] = 1;
      dfs(to);
    } else if (col[to] == 1) {
      res[ind] = 2;
      cyc = true;
    } else {
      res[ind] = 1;
    }
  }
  col[r] = 2;
}
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cin >> n >> m;
  for (long long i = 0; i < m; ++i) {
    long long u, v;
    cin >> u >> v;
    --u, --v;
    g[u].push_back({v, i});
  }
  for (long long i = 0; i < n; ++i) {
    if (col[i] == 0) {
      dfs(i);
    }
  }
  cout << (cyc ? 2 : 1) << '\n';
  for (long long i = 0; i < m; ++i) {
    cout << res[i] << ' ';
  }
}
