#define DEBUG 0
/**
 * File    : B2.cpp
 * Author  : Kazune Takahashi
 * Created : 7/15/2019, 2:30:15 AM
 * Powered by Visual Studio Code
 */
#include <iostream>
#include <iomanip>
#include <algorithm>
#include <vector>
#include <string>
#include <complex>
#include <tuple>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <unordered_map>
#include <unordered_set>
#include <bitset>
#include <functional>
#include <random>
#include <chrono>
#include <cctype>
#include <cassert>
#include <cmath>
#include <cstdio>
#include <cstdlib>
using namespace std;
#define maxs(x, y) (x = max(x, y))
#define mins(x, y) (x = min(x, y))
using ll = long long;
class mint
{
public:
  static ll MOD;
  ll x;
  mint() : x(0) {}
  mint(ll x) : x(x % MOD) {}
  mint operator-() const { return x ? MOD - x : 0; }
  mint &operator+=(const mint &a)
  {
    if ((x += a.x) >= MOD)
    {
      x -= MOD;
    }
    return *this;
  }
  mint &operator-=(const mint &a) { return *this += -a; }
  mint &operator*=(const mint &a)
  {
    (x *= a.x) %= MOD;
    return *this;
  }
  mint &operator/=(const mint &a) { return (*this *= power(MOD - 2)); }
  mint operator+(const mint &a) const { return mint(*this) += a; }
  mint operator-(const mint &a) const { return mint(*this) -= a; }
  mint operator*(const mint &a) const { return mint(*this) *= a; }
  mint operator/(const mint &a) const { return mint(*this) /= a; }
  bool operator<(const mint &a) const { return x < a.x; }
  bool operator==(const mint &a) const { return x == a.x; }
  const mint power(ll N)
  {
    if (N == 0)
    {
      return 1;
    }
    else if (N % 2 == 1)
    {
      return *this * power(N - 1);
    }
    else
    {
      mint half = power(N / 2);
      return half * half;
    }
  }
};
ll mint::MOD = 1e9 + 7;
istream &operator>>(istream &stream, mint &a) { return stream >> a.x; }
ostream &operator<<(ostream &stream, const mint &a) { return stream << a.x; }
class combination
{
public:
  vector<mint> inv, fact, factinv;
  static int MAX_SIZE;
  combination() : inv(MAX_SIZE), fact(MAX_SIZE), factinv(MAX_SIZE)
  {
    inv[1] = 1;
    for (auto i = 2; i < MAX_SIZE; i++)
    {
      inv[i] = (-inv[mint::MOD % i]) * (mint::MOD / i);
    }
    fact[0] = factinv[0] = 1;
    for (auto i = 1; i < MAX_SIZE; i++)
    {
      fact[i] = mint(i) * fact[i - 1];
      factinv[i] = inv[i] * factinv[i - 1];
    }
  }
  mint operator()(int n, int k)
  {
    if (n >= 0 && k >= 0 && n - k >= 0)
    {
      return fact[n] * factinv[k] * factinv[n - k];
    }
    return 0;
  }
};
int combination::MAX_SIZE = 1e6 + 10;
ll gcd(ll x, ll y) { return y ? gcd(y, x % y) : x; }
// const double epsilon = 1e-10;
// const ll infty = 1000000000000000LL;
// const int dx[4] = {1, 0, -1, 0};
// const int dy[4] = {0, 1, 0, -1};

class UnionFind
{
  vector<long long> par;

public:
  UnionFind() {}
  UnionFind(int n) : par(n, -1) {}

  bool is_same(int x, int y)
  {
    return root(x) == root(y);
  }

  bool merge(int x, int y)
  {
    x = root(x);
    y = root(y);
    if (x == y)
    {
      return false;
    }
    if (par[x] > par[y])
    {
      swap(x, y);
    }
    par[x] += par[y];
    par[y] = x;
    return true;
  }

  long long size(int x)
  {
    return -par[root(x)];
  }

private:
  int root(int x)
  {
    if (par[x] < 0)
    {
      return x;
    }
    return par[x] = root(par[x]);
  }
};

using edge = tuple<int, int>;

int N, M;
vector<edge> E;
vector<edge> ans;
int cnt[100010];
vector<int> V[100010];

void Yes()
{
  for (auto x : ans)
  {
    cout << get<0>(x) + 1 << " " << get<1>(x) + 1 << endl;
  }
  exit(0);
}

void No()
{
  cout << "-1" << endl;
  exit(0);
}

void make_V()
{
  UnionFind uf{N};
  for (auto e : E)
  {
    int a, b;
    tie(a, b) = e;
    if (!uf.is_same(a, b))
    {
      uf.merge(a, b);
      V[a].push_back(b);
      V[b].push_back(a);
    }
    else
    {
      ans.push_back(e);
      cnt[a]++;
    }
  }
}

void dfs(int v, int p = -1)
{
  for (auto w : V[v])
  {
    if (p != w)
    {
      dfs(w, v);
    }
  }
  if (p == -1)
  {
    return;
  }
  if (cnt[v] % 2 == 1)
  {
    ans.push_back(edge(v, p));
    cnt[v]++;
  }
  else
  {
    ans.push_back(edge(p, v));
    cnt[p]++;
  }
}

void solve()
{
  make_V();
  dfs(0);
}

int main()
{
  cin >> N >> M;
  for (auto i = 0; i < M; i++)
  {
    int a, b;
    cin >> a >> b;
    --a;
    --b;
    E.push_back(edge(a, b));
  }
  if (M % 2 == 1)
  {
    No();
  }
  solve();
  Yes();
}

Measured memory_bytes: 15204