#include <bits/stdc++.h>
#include <unistd.h>

using namespace std;

#define DEBUG(x) cerr<<#x<<": "<<x<<endl;
#define DEBUG_VEC(v) cerr<<#v<<":";for(int i=0;i<v.size();i++) cerr<<" "<<v[i]; cerr<<endl
#define DEBUG_MAT(v) cerr<<#v<<endl;for(int i=0;i<v.size();i++){for(int j=0;j<v[i].size();j++) {cerr<<v[i][j]<<" ";}cerr<<endl;}


typedef long long ll;
#define vi vector<int>
#define vl vector<ll>
#define vii vector< vector<int> >
#define vll vector< vector<ll> >
#define vs vector<string>
#define pii pair<int,int>
#define pis pair<int,string>
#define psi pair<string,int>
#define pll pair<ll,ll>
template<class S, class T> pair<S, T> operator+(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first + t.first, s.second + t.second); }
template<class S, class T> pair<S, T> operator-(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first - t.first, s.second - t.second); }
template<class S, class T> ostream& operator<<(ostream& os, pair<S, T> p) { os << "(" << p.first << ", " << p.second << ")"; return os; }
#define X first
#define Y second
#define rep(i,n) for(int i=0;i<(n);i++)
#define rep1(i,n) for(int i=1;i<=(n);i++)
#define rrep(i,n) for(int i=(n)-1;i>=0;i--)
#define rrep1(i,n) for(int i=(n);i>0;i--)
#define REP(i,a,b) for(int i=a;i<b;i++)
#define in(x, a, b) (a <= x && x < b)
#define all(c) c.begin(),c.end()
template<class T> bool chmax(T &a, const T &b) { if (a<b) { a = b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a = b; return 1; } return 0; }
#define UNIQUE(v) v.erase(std::unique(v.begin(), v.end()), v.end());
const ll inf = 1000000001;
const ll INF = (ll)1e18 + 1;
const ll MOD = 1000000007;
//const ll MOD = 998244353;
const double pi = 3.14159265358979323846;
#define Sp(p) cout<<setprecision(15)<< fixed<<p<<endl;
int dx[4] = { -1,0, 1,0 }, dy[4] = { 0,1,0,-1 };
int dx2[8] = { 1,1,0,-1,-1,-1,0,1 }, dy2[8] = { 0,1,1,1,0,-1,-1,-1 };
#define fio() cin.tie(0); ios::sync_with_stdio(false);
// #define mp make_pair
//#define endl '\n'

const int N = 111111;
vi used(N);
vii G(N);
vi perm;

void dfs(int u) {
  used[u] = true;
  rep (i, G[u].size()) {
    if (used[G[u][i]]) continue;
    dfs(G[u][i]);
  }
  perm.push_back(u);
}

int main() {
  int n, m;
  cin >> n >> m;
  if (m % 2) {
    cout << -1 << endl;
    return 0;
  }

  vector<set<int>> st(n);
  rep (i, m) {
    int u, v;
    cin >> u >> v;
    u--; v--;
    st[u].insert(v);
    st[v].insert(u);
    G[u].push_back(v);
    G[v].push_back(u);
  }

  dfs(0);
  // DEBUG_VEC(perm);
  
  vi score(n);
  vector<pii> ans;
  rep (i, n - 2) {
    int u = perm[i];
    if (score[u] % 2 == 0) {
      for (auto itr = st[u].begin(); itr != st[u].end(); itr++) {
        int v = *itr;
        score[v]++;
        st[v].erase(u);
        ans.push_back(pii(v, u));
      }
    }
    else {
      auto itr = st[u].begin();
      int v = *itr;
      score[u]++;
      st[v].erase(u);
      ans.push_back(pii(u, v));
      itr++;
      for (; itr != st[u].end(); itr++) {
        int v = *itr;
        score[v]++;
        st[v].erase(u);
        ans.push_back(pii(v, u));
      }        
    }
  }

  int u = perm[n - 2], v = perm[n - 1];
  assert(score[u] % 2 != score[v] % 2);
  if (score[u] % 2) {
    ans.push_back(pii(u, v));
  }
  else {
    ans.push_back(pii(v, u));
  }
  assert(ans.size() == m);
  rep (i, ans.size()) {
    cout << ans[i].first + 1 << " " << ans[i].second + 1 << endl;
  }
}


Measured memory_bytes: 26484