#include <bits/stdc++.h>
using namespace std;
 
#define int long long
#define pb push_back
#define ub upper_bound
#define lb upper_bound
#define mp make_pair
#define F first
#define S second
#define FOR(i,a,b) for(int (i)=(a);(i)<(b);(i)++)
#define REP(i,n) FOR(i,0,n)
#define ALL(a) (a).begin(),(a).end()
#define RALL(a) (a).rbegin(),(a).rend()
#define SORT(c) sort((c).begin(),(c).end())
#define ve vector
#define vi vector<int>
#define vp vector<pair<int,int>>
#define vvi vector<vector<int>>
 
using ll = long long;
const ll INF = LLONG_MAX - 100;
ll mod = 1e9 + 7;
int dx[] = {-1,0,1,0}, dy[] = {0,1,0,-1};
vector<ll> prime;

class fact {
public:
	int fmod = 1e9+7;
	vector<int> fac, inv;
	fact (int n, int Mod = 1e9+7) {
		fmod = Mod;
		fac = vector<int>(n,0);
		inv = vector<int>(n,0);
		fac[0] = 1; for (int i = 1; i < n; i++) fac[i] = fac[i-1] * i % fmod;
		for (int i = 0;i < n;i++) inv[i] = fact::POW(fac[i],fmod-2);
	}
	ll nCr(ll n, ll r) {return (fac[n] * inv[r] % fmod) * inv[n-r] % fmod;}
	ll POW(ll a, ll b) {ll c = 1; while (b > 0) {if (b & 1) {c = a * c%fmod;}a = a * a%fmod; b >>= 1;}return c;}
};
 
template <class T = ll> T in() {T x; cin >> x; return (x);}
void DEBUG(vector<int> a) {for(int i=0;i<a.size();i++)cout<<a[i]<<" ";cout<<endl;}
void EMP(int x) {cout<<"!!!"<<x<<"!!!"<<endl;}
ll GCD(ll a, ll b) {ll c; while (b != 0) {c = a % b; a = b; b = c;}return a;}
ll LCM(ll a, ll b) {return a * b / GCD(a, b);}
ll POW(ll a, ll b) {ll c = 1; while (b > 0) {if (b & 1) {c = a * c%mod;}a = a * a%mod; b >>= 1;}return c;}
void PRI(ll n) {bool a[n + 1LL]; for (int i = 0; i < n + 1LL; i++) {a[i] = 1LL;}for (int i = 2; i < n + 1LL; i++) {if (a[i]) {prime.pb(i); ll b = i; while (b <= n) {a[b] = 0; b += i;}}}}
template <typename T> T chmin(T& a, T b) {if(a>b)a=b;return a;}
template <typename T> T chmax(T& a, T b) {if(a<b)a=b;return b;}
bool isSqrt(ll a) {return pow(sqrt(a),2) == a ? 1 : 0;}
void YesNo(bool a) {if (a) cout << "Yes"; else cout << "No"; cout << endl;}
void yesno(bool a) {if (a) cout << "yes"; else cout << "no"; cout << endl;}
void YESNO(bool a) {if (a) cout << "YES"; else cout << "NO"; cout << endl;}

set<int> to[100005];
vector<int> cnt(100005,0);
vector<bool> visited(100005,false);
vector<pair<int,int>> ans;
void dfs(int A, int from) {
    if (visited[A]) return;
    visited[A] = true;
    for (auto&& To : to[A]) {
        int go = To;
        if (go == from) continue;
        if (visited[To]) {
            ans.push_back({A+1,go+1});
            cnt[A]++;
            to[A].erase(go);
            to[go].erase(A);
        } else {
            dfs(go,A);
        }
    }
    if (cnt[A] % 2 == 0) {
        ans.push_back({from+1,A+1});
        cnt[from]++;
        int go = *to[A].begin();
        to[A].erase(go); to[go].erase(A);
    } else {
        ans.push_back({A+1,from+1});
        cnt[A]++;
        int go = *to[A].begin();
        to[A].erase(go); to[go].erase(A);
    }
    return;
}

bool solve() {
	int n,m; cin >> n >> m;
    REP (i,m) {
        int a,b; cin >> a >> b;
        to[--a].insert(--b); to[b].insert(a);
    }
    if (m % 2 == 1) {
        cout << -1 << endl;
    } else {
        vector<int> go;
        for (auto&& A : to[0]) {
            go.push_back(A);
        }
        visited[0] = true;
        for (auto&& A : go) {
            dfs(A,0);
        }
        for (auto&& A : ans) {
            cout << A.first << " " << A.second << endl;
        }
    }
}

signed main() {
	cin.tie(0);
	ios::sync_with_stdio(false);
	solve();
}


Measured memory_bytes: 27264