#include <bits/stdc++.h>
using namespace std;
const char el = '\n';
int deg[100001];
int assignment[100001];
bool seen[100001];
int other(int x, int y) {
  vector<bool> v(4, true);
  v[x] = false;
  v[y] = false;
  for (int i = 1; i <= 3; ++i) {
    if (v[i]) return i;
  }
  return 0;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int n, m;
  cin >> n >> m;
  vector<set<int>> nbr(n + 1);
  fill(deg + 1, deg + 1 + n, 0);
  for (int i = 0; i < m; ++i) {
    int u, v;
    cin >> u >> v;
    ++deg[u], ++deg[v];
    nbr[u].emplace(v);
    nbr[v].emplace(u);
  }
  vector<int> numwithassignment(4, 0);
  int assigned = 0;
  assignment[1] = 1;
  ++numwithassignment[1];
  seen[1] = true;
  ++assigned;
  if (nbr[1].empty()) {
    cout << -1 << el;
    return 0;
  }
  stack<pair<int, int>> s;
  int temp = *nbr[1].begin();
  assignment[temp] = 2;
  ++numwithassignment[2];
  seen[temp] = true;
  ++assigned;
  s.push({temp, 1});
  for (int j : nbr[1]) {
    if (j == temp) continue;
    if (nbr[temp].count(j)) {
      assignment[j] = 3;
    } else {
      assignment[j] = 2;
    }
    ++numwithassignment[assignment[j]];
    seen[j] = true;
    ++assigned;
    s.push({j, 1});
  }
  while (!s.empty()) {
    auto pr = s.top();
    s.pop();
    int i = pr.first, j = pr.second;
    for (int k : nbr[i]) {
      if (seen[k]) {
        if (assignment[k] == assignment[i]) {
          cout << -1 << el;
          return 0;
        } else if (nbr[j].count(k)) {
          if (assignment[k] == assignment[j]) {
            cout << -1 << el;
            return 0;
          }
        } else {
          if (assignment[k] != assignment[j]) {
            cout << -1 << el;
            return 0;
          }
        }
      } else {
        if (nbr[j].count(k)) {
          assignment[k] = other(assignment[j], assignment[i]);
        } else {
          assignment[k] = assignment[j];
        }
        ++numwithassignment[assignment[k]];
        s.push({k, i});
        seen[k] = true;
        ++assigned;
      }
    }
  }
  if (assigned < n) {
    cout << -1 << el;
    return 0;
  }
  for (int i = 1; i <= 3; ++i) {
    if (numwithassignment[i] == 0) {
      cout << -1 << el;
      return 0;
    }
  }
  vector<int> complement(4, 0);
  complement[1] = numwithassignment[2] + numwithassignment[3];
  complement[2] = numwithassignment[1] + numwithassignment[3];
  complement[3] = numwithassignment[1] + numwithassignment[2];
  for (int u = 1; u <= n; ++u) {
    int j = assignment[u];
    if (deg[u] != complement[j]) {
      cout << -1 << el;
      return 0;
    }
  }
  for (int u = 1; u <= n; ++u) {
    cout << assignment[u] << " ";
  }
  cout << el;
}
