// includes
#include <bits/stdc++.h>
using namespace std;

// macros
#define pb emplace_back
#define mk make_pair
#define FOR(i, a, b) for(int i=(a);i<(b);++i)
#define rep(i, n) FOR(i, 0, n)
#define rrep(i, n) for(int i=((int)(n)-1);i>=0;i--)
#define irep(itr, st) for(auto itr = (st).begin(); itr != (st).end(); ++itr)
#define irrep(itr, st) for(auto itr = (st).rbegin(); itr != (st).rend(); ++itr)
#define whole(x) (x).begin(),(x).end()
#define sz(x) ((int)(x).size())
#define bit(n) (1LL<<(n))
#define F first
#define S second
// functions
template <typename T> void unique(T& c){c.erase(std::unique(c.begin(), c.end()), 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;}
template <typename T> istream &operator>>(istream &is, vector<T> &vec){for(auto &v: vec)is >> v; return is;}
template <typename T> ostream &operator<<(ostream &os, const vector<T>& vec){for(int i = 0; i < vec.size(); i++){ os << vec[i]; if(i + 1 != vec.size())os << " ";} return os;}
template <typename T> ostream &operator<<(ostream &os, const set<T>& st){for(auto itr = st.begin(); itr != st.end(); ++itr){ os << *itr; auto titr = itr; if(++titr != st.end())os << " ";} return os;}
template <typename T> ostream &operator<<(ostream &os, const unordered_set<T>& st){for(auto itr = st.begin(); itr != st.end(); ++itr){ os << *itr; auto titr = itr; if(++titr != st.end())os << " ";} return os;}
template <typename T> ostream &operator<<(ostream &os, const multiset<T>& st){for(auto itr = st.begin(); itr != st.end(); ++itr){ os << *itr; auto titr = itr; if(++titr != st.end())os << " ";} return os;}
template <typename T> ostream &operator<<(ostream &os, const unordered_multiset<T>& st){for(auto itr = st.begin(); itr != st.end(); ++itr){ os << *itr; auto titr = itr; if(++titr != st.end())os << " ";} return os;}
template <typename T1, typename T2> ostream &operator<<(ostream &os, const pair<T1, T2> &p){os << "(" << p.first << ", " << p.second << ")"; return os;}
template <typename T1, typename T2> ostream &operator<<(ostream &os, const map<T1, T2> &mp){for(auto itr = mp.begin(); itr != mp.end(); ++itr){ os << "(" << itr->first << ", " << itr->second << ")"; auto titr = itr; if(++titr != mp.end())os << " "; } return os;}
template <typename T1, typename T2> ostream &operator<<(ostream &os, const unordered_map<T1, T2> &mp){for(auto itr = mp.begin(); itr != mp.end(); ++itr){ os << "(" << itr->first << ", " << itr->second << ")"; auto titr = itr; if(++titr != mp.end())os << " "; } return os;}
//  types
using ll = long long int;
using P = pair<int, int>;
// constants
const int inf = 1e9;
const ll linf = 1LL << 60;
const double EPS = 1e-10;
const int mod = 1000000007;
const int dx[4] = {-1, 0, 1, 0};
const int dy[4] = {0, -1, 0, 1};
// io
struct fast_io{
  fast_io(){ios_base::sync_with_stdio(false); cin.tie(nullptr); cout << fixed << setprecision(20);}
} fast_io_;

vector<int> edge[100010], child[100010];
int par[100010];

bool used[100010];
void dfs(int i){
  used[i] = true;
  for(auto e: edge[i]){
    if(used[e])continue;
    par[e] = i;
    child[i].pb(e);
    dfs(e);
  }
}

int res[100010], cnt[100010];
map<P, int> idx;
int u[100010], v[100010];

void dfs2(int i){
  for(auto e: child[i])dfs2(e);
  if(i == 0)return;
  if(cnt[i] % 2 == 1){
    int id = idx[mk(i, par[i])];
    res[id] = (res[id] == u[id]) ? v[id]: u[id];
    cnt[u[id]]++;
    cnt[v[id]]++;
  }
}

int main(int argc, char const* argv[])
{
  int n, m; cin >> n >> m;
  rep(i, m){
    int a, b; cin >> a >> b; a--; b--;
    res[i] = a;
    cnt[a]++;
    edge[a].pb(b);
    edge[b].pb(a);
    u[i] = a, v[i] = b;
    idx[mk(u[i], v[i])] = i;
    idx[mk(v[i], u[i])] = i;
  }
  dfs(0);
  dfs2(0);
  bool ok = true;
  rep(i, n){
    if(cnt[i] % 2 != 0)ok = false;
  }
  if(!ok){
    cout << -1 << endl;
  }else{
    rep(i, m){
      if(u[i] == res[i])cout << u[i] + 1 << " " << v[i] + 1 << endl;
      else cout << v[i] + 1 << " " << u[i] + 1 << endl;
    }
  }
  return 0;
}


Measured memory_bytes: 36224