#include <bits/stdc++.h>
using namespace std;
const long long N = 100005;
char en = '\n';
long long inf = 1e16;
long long mod = 1e9 + 7;
long long power(long long x, long long n, long long mod) {
  long long res = 1;
  x %= mod;
  while (n) {
    if (n & 1) res = (res * x) % mod;
    x = (x * x) % mod;
    n >>= 1;
  }
  return res;
}
int32_t main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  long long n, m;
  cin >> n >> m;
  map<pair<long long, long long>, long long> edges;
  map<long long, long long> adj[n + 5];
  for (long long i = 1; i <= m; i++) {
    long long a, b;
    cin >> a >> b;
    if (a > b) swap(a, b);
    adj[a][b];
    adj[b][a];
    edges[{a, b}];
  }
  bool visited[n + 5];
  memset(visited, false, sizeof(visited));
  vector<long long> arr[3];
  arr[0].push_back(1);
  visited[1] = true;
  for (long long i = 1; i <= n; i++) {
    if (i == 1) continue;
    if (!adj[1].count(i)) {
      visited[i] = true;
      arr[0].push_back(i);
    }
  }
  long long i;
  for (i = 1; i <= n; i++) {
    if (!visited[i]) {
      break;
    }
  }
  if (i == n + 1) {
    cout << -1 << en;
    return 0;
  }
  visited[i] = true;
  arr[1].push_back(i);
  for (long long j = 1; j <= n; j++) {
    if (j == i) continue;
    if (visited[j] or adj[i].count(j)) continue;
    arr[1].push_back(j);
    visited[j] = true;
  }
  for (i = 1; i <= n; i++) {
    if (!visited[i]) arr[2].push_back(i);
  }
  long long cnt2 = 0;
  for (long long i = 0; i <= 2; i++) {
    for (long long j = i + 1; j <= 2; j++) {
      cnt2 += (long long)arr[i].size() * arr[j].size();
    }
  }
  if (cnt2 != m) {
    cout << -1 << en;
    return 0;
  }
  long long ans[n + 5];
  for (long long i = 0; i <= 2; i++) {
    if (arr[i].size() == 0) {
      cout << -1 << en;
      return 0;
    }
    for (long long x : arr[i]) ans[x] = i + 1;
    for (long long j = i + 1; j <= 2; j++) {
      for (long long &x : arr[i]) {
        for (long long &y : arr[j]) {
          if (!edges.count({min(x, y), max(x, y)})) {
            cout << -1 << en;
            return 0;
          }
        }
      }
    }
  }
  for (long long i = 1; i <= n; i++) cout << ans[i] << " ";
  cout << en;
  return 0;
}
