#include <bits/stdc++.h>
using namespace std;
const int N = 2e5;
vector<int> g[N], used, g1[N];
int gl[N];
bool ok = 1;
void dfs(int v, int glb) {
  used[v] = 1;
  gl[v] = glb;
  for (int to : g[v])
    if (!used[to]) dfs(to, glb + 1);
}
void dfs1(int v, int root) {
  used[v] = 1;
  for (int to : g1[v])
    if (to == root)
      ok = 0;
    else if (!used[to])
      dfs1(to, root);
}
int32_t main() {
  ios_base::sync_with_stdio(NULL);
  cin.tie(0);
  cout.tie(0);
  int n, m;
  cin >> n >> m;
  map<pair<int, int>, int> q;
  for (int i = 0; i < m; ++i) {
    int a, b;
    cin >> a >> b;
    --a;
    --b;
    q[make_pair(a, b)] = i;
    g[a].push_back(b);
    g[b].push_back(a);
    g1[a].push_back(b);
  }
  for (int i = 0; i < n; ++i) {
    used.assign(n, 0);
    dfs1(i, i);
  }
  used.assign(n, 0);
  for (int i = 0; i < n; ++i)
    if (!used[i]) dfs(i, 0);
  if (ok) {
    cout << "1\n";
    for (int i = 0; i < m; ++i) cout << "1 ";
    return 0;
  }
  vector<int> res(m);
  for (auto x : q) {
    int a = x.first.first;
    int b = x.first.second;
    if (gl[a] > gl[b])
      res[x.second] = 1;
    else
      res[x.second] = 2;
  }
  cout << "2\n";
  for (int i = 0; i < m; ++i) cout << res[i] << " ";
}
