#include <bits/stdc++.h>
#pragma GCC optimize(3)
using namespace std;
const double PI = acos(-1.0);
const double eps = 1e-6;
struct Edge {
  int to, nxt;
} edge[100005];
int n, m, cnt, head[100005], in[100005], out[100005];
queue<int> q;
pair<int, int> edges[100005];
inline int read() {
  int x = 0, f = 1;
  char ch = getchar();
  while (ch < '0' || ch > '9') {
    if (ch == '-') f = -1;
    ch = getchar();
  }
  while (ch >= '0' && ch <= '9') {
    x = x * 10 + ch - '0';
    ch = getchar();
  }
  return x * f;
}
void addedge(int u, int v) {
  edge[cnt].to = v;
  edge[cnt].nxt = head[u];
  head[u] = cnt++;
  return;
}
template <typename T>
void debug(T x) {
  cout << "value=" << x << endl;
  return;
}
signed main() {
  memset(head, -1, sizeof(head));
  n = read(), m = read();
  for (int i = 1; i <= m; i++) {
    int u = read(), v = read();
    edges[i].first = u;
    edges[i].second = v;
    addedge(u, v);
    out[u]++;
    in[v]++;
  }
  int tot = 0;
  for (int i = 1; i <= n; i++) {
    if (in[i] == 0) {
      q.push(i);
      tot++;
    }
  }
  while (!q.empty()) {
    int u = q.front();
    q.pop();
    for (int k = head[u]; k != -1; k = edge[k].nxt) {
      int v = edge[k].to;
      in[v]--;
      if (!in[v]) {
        q.push(v);
        tot++;
      }
    }
  }
  if (tot == n) {
    cout << 1 << endl;
    for (int i = 1; i <= m; i++) printf("1 ");
  } else {
    cout << 2 << endl;
    for (int i = 1; i <= m; i++) {
      if (edges[i].first < edges[i].second)
        printf("1 ");
      else
        printf("2 ");
    }
  }
  return 0;
}
