#include<algorithm>
#include<bitset>
#include<cmath>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<ctime>
#include<deque>
#include<fstream>
#include<iomanip>
#include<iostream>
#include<map>
#include<queue>
#include<set>
#include<stack>
#include<unordered_map>
#include<unordered_set>
#include<utility>
#include<vector>

using namespace std;

#define dbg(x) (cout<<#x<<" = "<<(x)<<'\n')
#ifdef HOME
const string inputFile = "input.txt";
const string outputFile = "output.txt";
#else
const string problemName = "felinare";
const string inputFile = problemName + ".in";
const string outputFile = problemName + ".out";
#endif

typedef long long int lld;
typedef pair<int, int> PII;
typedef pair<int, lld> PIL;
typedef pair<lld, int> PLI;
typedef pair<lld, lld> PLL;

const int INF = (1LL << 31) - 1;
const lld LINF = (1LL << 62) - 1;
const int dx[] = {1, 0, -1, 0, 1, -1, 1, -1};
const int dy[] = {0, 1, 0, -1, 1, -1, -1, 1};
const int NMAX = 8191;

int N, M, sol, cupl;
vector<int> A[NMAX + 5];
vector<int> B[NMAX + 5];
int P[NMAX + 5];
int Q[NMAX + 5];
bitset < 2 * NMAX + 5 > viz;
int light[NMAX + 5];

int pair_up(int x) {
    if(viz[x])
        return 0;

    viz[x] = 1;

    for(auto y : A[x])
        if((!Q[y]) || pair_up(Q[y])) {
            P[x] = y;
            Q[y] = x;
            return 1;
        }

    return 0;
}

void dfs(int x) {
    viz[x] = 1;

    for(auto y : A[x])
        if(Q[y] != x && !viz[y + N]) {
            viz[y + N] = 1;
            dfs(Q[y]);
        }
}

int main() {
    int i, x, y, ok;

#ifndef ONLINE_JUDGE
    freopen(inputFile.c_str(), "r", stdin);
    freopen(outputFile.c_str(), "w", stdout);
#endif

    scanf("%d%d", &N, &M);

    while(M--) {
        scanf("%d%d", &x, &y);
        A[x].push_back(y);
        B[y].push_back(x);
    }

    do {
        viz = 0;
        ok = 0;

        for(i = 1; i <= N; i++)
            if(!P[i])
                ok |= pair_up(i);
    } while(ok);

    viz = 0;

    for(i = 1; i <= N; i++)
        if(!P[i])
            dfs(i);

    for(i = 1; i <= N; i++) {
        if(P[i])
            cupl++;

        if(!viz[i])
            light[i] |= 1;

        if(viz[i + N])
            light[i] |= 2;
    }

    printf("%d\n", 2 * N - cupl);

    for(i = 1; i <= N; i++)
        printf("%d\n", 3 ^ light[i]);

    return 0;
}