#include <bits/stdc++.h>
using namespace std;
void fast() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
}
int main() {
  fast();
  long long n, m;
  cin >> n >> m;
  vector<long long> g[n + 10];
  long long color[n + 10];
  long long siz[n + 10];
  bool no1[n + 10];
  for (int i = 1; i <= n; ++i) {
    color[i] = 0;
    no1[i] = 0;
  }
  long long u, v;
  for (int i = 1; i <= m; ++i) {
    cin >> u >> v;
    g[u].push_back(v);
    g[v].push_back(u);
    siz[u]++;
    siz[v]++;
  }
  if (siz[1] <= 1) {
    cout << -1;
    return 0;
  }
  color[1] = 1;
  v = 0;
  for (int i = 0; i < g[1].size(); ++i) no1[g[1][i]] = 1;
  for (int i = 1; i <= n; ++i)
    if (!no1[i]) color[i] = 1;
  for (int i = 1; i <= n; ++i)
    if (color[i] == 0) v = i;
  if (v == 0) {
    cout << -1;
    return 0;
  }
  if (siz[v] <= 1) {
    cout << -1;
    return 0;
  }
  for (int i = 1; i <= n; ++i) {
    no1[i] = 0;
  }
  for (int i = 0; i < g[v].size(); ++i) no1[g[v][i]] = 1;
  for (int i = 1; i <= n; ++i)
    if (!no1[i]) color[i] = 2;
  for (int i = 1; i <= n; ++i)
    if (!color[i]) color[i] = 3;
  long long sum[5];
  for (int i = 1; i <= 3; ++i) sum[i] = 0;
  for (int i = 1; i <= n; ++i) sum[color[i]]++;
  long long ans = sum[1] * sum[2] + sum[1] * sum[3] + sum[2] * sum[3];
  if (sum[1] == 0 || sum[2] == 0 || sum[3] == 0) {
    cout << -1;
    return 0;
  }
  if (ans != m) {
    cout << -1;
    return 0;
  }
  for (int i = 1; i <= n; ++i) {
    if (siz[i] <= 1) {
      cout << -1;
      return 0;
    }
    for (int j = 0; j < g[i].size(); ++j) {
      if (color[i] == color[g[i][j]]) {
        cout << -1;
        return 0;
      }
    }
  }
  for (int i = 1; i <= n; ++i) cout << color[i] << " ";
  return 0;
}
