#include <bits/stdc++.h>
using namespace std;
const int inf = 0x3f3f3f3f;
const int maxn = 5e3 + 10;
vector<int> topo;
int n, m;
vector<int> G[maxn];
int mp[maxn][maxn];
int x[maxn], y[maxn];
int f = 1;
bool topoSort() {
  int indgree[maxn] = {0};
  int visit[maxn] = {0};
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < G[i].size(); j++) {
      indgree[G[i][j]]++;
    }
  }
  int control = 0;
  while (control < n) {
    int u = 0, i;
    for (i = 0; i < n; i++) {
      if (!visit[i] && indgree[i] == 0) {
        u = i;
        break;
      }
    }
    if (i == n) {
      return false;
    }
    visit[u] = 1;
    topo.push_back(u);
    for (int j = 0; j < G[u].size(); j++) {
      indgree[G[u][j]]--;
    }
    control++;
  }
  return true;
}
int main() {
  cin >> n >> m;
  for (int i = 0; i < n; i++) {
    for (int j = i; j < n; j++) {
      mp[i][j] = 0;
      mp[j][i] = 1;
    }
  }
  for (int i = 0; i < m; i++) {
    cin >> x[i] >> y[i];
    x[i]--;
    y[i]--;
    G[x[i]].push_back(y[i]);
  }
  if (topoSort()) {
    cout << 1 << endl;
    for (int i = 0; i < m; i++) {
      cout << 1 << ' ';
    }
  } else {
    cout << 2 << endl;
    for (int i = 0; i < m; i++) {
      cout << mp[x[i]][y[i]] + 1 << ' ';
    }
  }
}
