// #pragma GCC optimize("Ofast")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native")
// #pragma GCC optimize("unroll-loops")
// #pragma GCC optimize("fast-math")

#include <bits/stdc++.h>

typedef unsigned long long ull;
typedef long long ll;
typedef long double ld;
// typedef __int128 tll;

// #define _CRT_DISABLE_PERFCRIT_LOCKS
#define rall(a) a.rbegin(), a.rend()
#define all(a) a.begin(), a.end()
#define pb push_back
#define pf push_front
#define forn(i, x) for (int i = 0; i < x; ++i)
#define int long long

using namespace std;

int cnt(int a, int b) {
    return a / b + (a % b > 0);
}

int intlog(double base, double x) {
    return ceil(log(x) / log(base));
}

int binpow(int n, int base) {
    if (base == 0) return 1;
    if (base == 1) return n;
    return (base % 2 == 1 ? binpow(n, base - 1) * n : binpow(n, base / 2) * binpow(n, base / 2));
}

signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    int n, m; cin >> n >> m;
    vector<set<int>> vst(n);
    set<int> fi, se, th;
    fi.insert(0);

    for (int i = 0; i < m; ++i) {
        int a, b; cin >> a >> b;
        --a, --b;
        vst[a].insert(b);
        vst[b].insert(a);
    }

    int sec = -1;

    for (int i = 1; i < n; ++i) if (!vst[i].count(0)) fi.insert(i);

    for (int i = 1; i < n; ++i) if (!fi.count(i)) sec = i;

    if (sec == -1) {
        cout << -1;
        exit(0);
    }

    se.insert(sec);

    for (int i = 1; i < n; ++i) if (!vst[i].count(sec)) se.insert(i);

    int thi = -1;

    for (int i = 1; i < n; ++i) if (!se.count(i) && !fi.count(i)) thi = i;

    if (thi == -1) {
        cout << -1;
        exit(0);
    }

    th.insert(thi);

    for (int i = 1; i < n; ++i) if (!vst[i].count(thi)) th.insert(i);

    if (se.size() + fi.size() + th.size() != n) {
        cout << -1;
        exit(0);
    }

    int s = se.size(), f = fi.size(), t = th.size();

    if ((s * (f + t) + f * (s + t) + t * (f + s)) / 2 != m) {
        cout << -1;
        exit(0);
    }

    for (int i = 0; i < n; ++i) {
        if (fi.count(i)) {
            cout << 1 << " ";
        } else if (se.count(i)) {
            cout << 2 << " ";
        } else if (th.count(i)) {
            cout << 3 << " ";
        }
    }
}