#include <bits/stdc++.h>
using namespace std;
int gcd(int a, int b) {
  if (b == 0)
    return a;
  else
    return gcd(b, a % b);
}
long long lcm(long long a, long long b) { return a / gcd(a, b) * b; }
int main() {
  ios_base::sync_with_stdio(false);
  int n, m;
  cin >> n >> m;
  vector<vector<int> > edges(n + 10, vector<int>());
  for (int i = 0; i < m; i++) {
    int x, y;
    cin >> x >> y;
    edges[x].push_back(y);
    edges[y].push_back(x);
  }
  map<int, int> not_first;
  map<int, int> not_second;
  map<int, int> not_third;
  set<int> first;
  set<int> second;
  set<int> third;
  for (int i = 1; i < n + 1; i++) {
    if (not_first.find(i) == not_first.end()) {
      first.insert(i);
      for (int j = 0; j < edges[i].size(); j++) {
        not_first[edges[i][j]]++;
      }
    } else if (not_second.find(i) == not_second.end()) {
      second.insert(i);
      for (int j = 0; j < edges[i].size(); j++) {
        not_second[edges[i][j]]++;
      }
    } else if (not_third.find(i) == not_third.end()) {
      third.insert(i);
      for (int j = 0; j < edges[i].size(); j++) {
        not_third[edges[i][j]]++;
      }
    } else {
      cout << -1;
      return 0;
    }
  }
  if (second.size() == 0 or third.size() == 0) {
    cout << -1;
  } else {
    for (auto i = not_first.begin(); i != not_first.end(); i++) {
      if (i->second != first.size()) {
        cout << -1;
        return 0;
      }
    }
    for (auto i = not_second.begin(); i != not_second.end(); i++) {
      if (i->second != second.size()) {
        cout << -1;
        return 0;
      }
    }
    for (auto i = not_third.begin(); i != not_third.end(); i++) {
      if (i->second != third.size()) {
        cout << -1;
        return 0;
      }
    }
    vector<int> cols(n + 1, 0);
    for (auto i = first.begin(); i != first.end(); i++) {
      cols[*i] = 1;
    }
    for (auto i = second.begin(); i != second.end(); i++) {
      cols[*i] = 2;
    }
    for (auto i = third.begin(); i != third.end(); i++) {
      cols[*i] = 3;
    }
    for (int i = 1; i < n + 1; i++) {
      cout << cols[i] << " ";
    }
  }
  return 0;
}
