#include <bits/stdc++.h>
#define maxN 8193
#define maxM 20002
#define pii pair < int, int >
#define mp make_pair
#define f first
#define s second
using namespace std;
int n, m, l, Pair[2 * maxN], vis[2 * maxN], val[maxN];
vector < int > V[maxN];
pii ans[maxN];
int Pairup(int x)
{
    int y, i = 0;
    if (vis[x])
        return 0;
    vis[x] = 1;
    for (i = 0; i < V[x].size(); ++ i)
        if (Pair[y = V[x][i]] == -1 || Pairup(Pair[y]))
        {
            Pair[x] = y;
            Pair[y] = x;
            ///d = y;
            return 1;
        }
    return 0;
}
void read()
{
    freopen("felinare.in", "r", stdin);
    scanf("%d %d", &n, &m);
    for (int i = 1; i <= m; ++ i)
    {
        int x, y;
        scanf("%d %d", &x, &y);
        V[x].push_back(y + n);
    }
}
void solve()
{
    int i;
    memset(Pair, -1, sizeof(Pair));
    for (i = 1; i <= n; ++ i)
        if (Pair[i] == -1 && !vis[i])
        {
            memset(vis, 0, sizeof(vis));
            Pairup(i);
        }

    for (i = 1; i <= n; ++ i)
        if (Pair[i] != -1)
        {
            ans[++ l] = mp(i, Pair[i]);
            val[i] = 2;
        }
        else
            val[i] = 3;
}
void write()
{
    freopen("felinare.out", "w", stdout);
    printf("%d\n", 2 * n - l);
    for (int i = 1; i <= n; ++ i)
        printf("%d\n", val[i]);
}
int main()
{
    read();
    solve();
    write();
    return 0;
}