#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 100;
int h[N], vis[N], n, m, k, ins[N];
int col[N];
int cnt;
struct edge {
  int to, next;
} e[N << 1];
void add(int u, int v) {
  e[++cnt] = (edge){v, h[u]};
  h[u] = cnt;
}
void dfs(int x) {
  vis[x] = 1;
  ins[x] = 1;
  for (int i = h[x]; i; i = e[i].next)
    if (!vis[e[i].to]) {
      dfs(e[i].to);
    } else if (ins[e[i].to]) {
      col[i] = 1;
    }
  ins[x] = 0;
}
int main() {
  scanf("%d%d", &n, &m);
  for (int i = 1; i <= m; i++) {
    int u, v;
    scanf("%d%d", &u, &v);
    add(u, v);
  }
  for (int i = 1; i <= n; i++)
    if (!vis[i]) dfs(i);
  int ans = 1;
  for (int i = 1; i <= cnt; i++) ans = max(ans, col[i] + 1);
  printf("%d\n", ans);
  for (int i = 1; i <= cnt; i++) printf("%d ", col[i] + 1);
  puts("");
}
