#ifndef _GLIBCXX_NO_ASSERT
#include <cassert>
#endif
#include <cctype>
#include <cerrno>
#include <cfloat>
#include <ciso646>
#include <climits>
#include <clocale>
#include <cmath>
#include <csetjmp>
#include <csignal>
#include <cstdarg>
#include <cstddef>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>

#if __cplusplus >= 201103L
#include <ccomplex>
#include <cfenv>
#include <cinttypes>
#include <cstdbool>
#include <cstdint>
#include <ctgmath>
#include <cwchar>
#include <cwctype>
#endif

// C++
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>

#if __cplusplus >= 201103L
#include <array>
#include <atomic>
#include <chrono>
#include <condition_variable>
#include <forward_list>
#include <future>
#include <initializer_list>
#include <mutex>
#include <random>
#include <ratio>
#include <regex>
#include <scoped_allocator>
#include <system_error>
#include <thread>
#include <tuple>
#include <typeindex>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
#endif
using namespace std;

typedef long long ll;
//typedef pair<int,int> Pint;
typedef pair<ll, ll> P;
//typedef pair<ll, pair<ll, ll>> P;
//typedef tuple<int,int,int> T;
typedef vector<ll> vec;
typedef vector<vec> mat;
#define rep(i, n) for(ll i = 0; i < n; i++)
#define revrep(i, n) for(ll i = n-1; i >= 0; i--)
#define pb push_back
#define f first
#define s second
const ll INFL = 1LL << 60;//10^18 = 2^60
const int INF = 1 << 30;//10^9
const ll MOD = 1e9 + 7;
//ll MOD  = 998244353;
vector<ll> dy = {0, 0, 1, -1, 1, 1, -1, -1, 0};
vector<ll> dx = {1, -1, 0, 0, 1, -1, 1, -1, 0};

ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
ll pow_long(ll x, ll k){
  ll res = 1;
  while(k > 0){
    if(k % 2) res *= x;
    x *= x;
    k /= 2;
  }
  return res;
}

ll pow_mod(ll x, ll k){
  x %= MOD; x += MOD; x %= MOD;
  ll res = 1;
  while(k > 0){
    if(k % 2){
      res *= x; res %= MOD;
    }
    x *= x; x %= MOD;
    k /= 2;
  }
  return res;
}
ll inverse(ll x){return pow_mod(x, MOD - 2);};


ll gcd(ll a, ll b){
    if(b == 0) return a;
    return gcd(b, a % b);
}

ll lcm(ll x, ll y){return x / gcd(x, y) * y;};

ll N, M;
vector<ll> A(100010), B(100010);
vector<ll> cnt(100010);
vector<ll> par(100010);
vector<ll> E[100010];
vector<bool> visited(100010);
vector<ll> d(100010);
vector<pair<ll, ll>> dv;
void dfs(ll now, ll from){
  visited[now] = 1;
  par[now] = from;
  for(ll x : E[now]){
    if(visited[x]) continue;
    d[x] = d[now] + 1;
    dfs(x, now);
  }
}

map<pair<ll, ll>, int> dir;

int main(void){
  cin >> N >> M;
  rep(i, M){
    cin >> A[i] >> B[i];
    A[i]--, B[i]--;
    E[A[i]].pb(B[i]);
    E[B[i]].pb(A[i]);
    cnt[A[i]]++;
    dir[{A[i], B[i]}] = 0;
    dir[{B[i], A[i]}] = 0;
    //偶数で A -> B
  }
  if(M % 2){
    cout << -1 << endl;
    return 0;
  }
  visited[0] = 1;
  d[0] = 0;
  dfs(0, -1);
  dv.resize(N);
  rep(i, N){
    dv[i].f = d[i];
    dv[i].s = i;
  }
  sort(dv.begin(), dv.end());
  reverse(dv.begin(), dv.end());
  rep(i, N){
    if(cnt[dv[i].s] % 2){
      dir[{dv[i].s, par[dv[i].s]}]++;
      cnt[dv[i].s]++;
      cnt[par[dv[i].s]]++;
    }
  }
  rep(i, M){
    if((dir[{A[i], B[i]}] + dir[{B[i], A[i]}]) % 2){
      cout << B[i] + 1 << " " << A[i] + 1 << endl;
    }else{
      cout << A[i] + 1 << " " << B[i] + 1 << endl;
    }
  }

}


Measured memory_bytes: 29568