#include <bits/stdc++.h>
using namespace std;
const int INF = 0x3f3f3f3f;
const long long int LINF = 0x3f3f3f3f3f3f3f;
set<int> adj[100009];
int st[100009];
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  int n, m;
  cin >> n >> m;
  for (int i = 0; i < n; i++) st[i] = 7;
  for (int i = 0; i < m; i++) {
    int u, v;
    cin >> u >> v;
    u--;
    v--;
    adj[u].insert(v);
    adj[v].insert(u);
  }
  vector<int> gid(n, -1);
  vector<int> grp[4];
  for (int g = 1; g <= 3; g++) {
    int fst;
    for (int i = 0; i < n; i++) {
      if (gid[i] == -1) {
        fst = i;
        break;
      }
    }
    grp[g].push_back(fst);
    gid[fst] = g;
    for (int i = 0; i < n; i++) {
      if (gid[i] != -1 || i == fst) continue;
      if (adj[fst].find(i) == adj[fst].end()) {
        gid[i] = g;
        grp[g].push_back(i);
      }
    }
  }
  for (int i = 0; i < n; i++) {
    if (gid[i] == -1) {
      cout << -1 << "\n";
      return 0;
    }
  }
  int cnt = 0;
  for (int g1 = 1; g1 <= 3; g1++)
    for (int g2 = g1 + 1; g2 <= 3; g2++)
      for (int v1 : grp[g1])
        for (int v2 : grp[g2]) {
          if (adj[v1].find(v2) == adj[v1].end()) {
            cout << -1 << "\n";
            return 0;
          }
          cnt++;
        }
  if (cnt != m) {
    cout << -1 << "\n";
    return 0;
  }
  for (int i = 0; i < gid.size(); i++)
    cout << gid[i] << " \n"[i == gid.size() - 1];
}
