#include <bits/stdc++.h>
using namespace std;
const int dy[] = {-1, 0, 1, 0}, dx[] = {0, 1, 0, -1};
const double EPS = 1e-8;
const double PI = acos(-1.0);
int popcount(int n) { return __builtin_popcount(n); }
int popcount(long long n) { return __builtin_popcountll(n); }
template <class T>
int SIZE(T a) {
  return a.size();
}
template <class T>
string IntToString(T num) {
  string res;
  stringstream ss;
  ss << num;
  return ss.str();
}
template <class T>
T StringToInt(string str) {
  T res = 0;
  for (int i = 0; i < SIZE(str); i++) res = (res * 10 + str[i] - '0');
  return res;
}
template <class T>
T gcd(T a, T b) {
  if (b == 0) return a;
  return gcd(b, a % b);
}
template <class T>
T lcm(T a, T b) {
  return a / gcd(a, b) * b;
}
template <class T>
void PrintSeq(T &a, int sz) {
  for (int i = 0; i < sz; i++) {
    cout << a[i];
    if (sz == i + 1)
      cout << endl;
    else
      cout << ' ';
  }
}
bool EQ(double a, double b) { return abs(a - b) < EPS; }
void fastStream() {
  cin.tie(0);
  std::ios_base::sync_with_stdio(0);
}
vector<string> split(string str, char del) {
  vector<string> res;
  for (int i = 0, s = 0; i < SIZE(str); i++) {
    if (str[i] == del) {
      if (i - s != 0) res.push_back(str.substr(s, i - s));
      s = i + 1;
    } else if (i == SIZE(str) - 1) {
      res.push_back(str.substr(s));
    }
  }
  return res;
}
class TimeWatch {
  clock_t start_, end_;

 public:
  void start() { start_ = clock(); }
  double stop() { return (double)(clock() - start_) / CLOCKS_PER_SEC; }
};
int N, M;
set<pair<int, int> > exists;
int main() {
  TimeWatch tw;
  tw.start();
  cin >> N >> M;
  for (int i = 0; i < M; i++) {
    int a, b;
    cin >> a >> b;
    a--;
    b--;
    if (a > b) swap(a, b);
    exists.insert(pair<int, int>(a, b));
  }
  vector<int> seq;
  for (int i = 0; i < N; i++) seq.push_back(i);
  while (1) {
    random_shuffle(seq.begin(), seq.end());
    bool ok = true;
    for (int i = 0; i < M; i++) {
      int a = seq[i];
      int b = seq[(i + 1) % N];
      if (a > b) swap(a, b);
      pair<int, int> p = pair<int, int>(a, b);
      if (exists.count(p)) {
        ok = false;
        break;
      }
    }
    if (ok) {
      for (int i = 0; i < M; i++) {
        int a = seq[i];
        int b = seq[(i + 1) % N];
        if (a > b) swap(a, b);
        a++;
        b++;
        cout << a << " " << b << endl;
      }
      return 0;
    }
    if (tw.stop() >= 2.7) {
      cout << -1 << endl;
      return 0;
    }
  }
  return 0;
}
