using System;
using System.Collections.Generic;
using System.Collections;
using System.Collections.Specialized;
using System.Linq;
using System.Text;
using System.IO;
using System.Reflection;
using static System.Math;
using System.Numerics;
static class Program{
	const int mod=(int)1e9+7;
	static List<Tuple<int,int>>[] li;
	static bool[] b,c;
	static int[] h;
	static StringBuilder sb=new StringBuilder();
	static void Main(){
		Sc sc=new Sc();
		int[] s=sc.Ia;
		int n=s[0],m=s[1];
		li=new List<Tuple<int,int>>[n+1];
		b=new bool[n+1];
		c=new bool[m];
		h=new int[n+1];
		for(int i=1;i<=n;i++){li[i]=new List<Tuple<int,int>>();}
		for(int i=0;i<m;i++){
			int[] e=sc.Ia;
			li[e[0]].Add(Tuple.Create(e[1],i));
			li[e[1]].Add(Tuple.Create(e[0],i));
		}
		if(m%2==1){Console.WriteLine("{0}",-1);}
		else{Fu(1,-1);Console.Write(sb);}
	}
	static void Fu(int a,int g){
		b[a]=true;
		for(int i=0;i<li[a].Count;i++){
			if(!b[li[a][i].Item1]){
				Fu(li[a][i].Item1,a);
				if(h[li[a][i].Item1]%2==0){
					sb.Append(a.ToString()+" "+li[a][i].Item1.ToString()+"\n");
					h[a]++;
				}
				else{
					sb.Append(li[a][i].Item1.ToString()+" "+a.ToString()+"\n");
					h[li[a][i].Item1]++;
				}
			}
			else if(!c[li[a][i].Item2]&&li[a][i].Item1!=g){
				c[li[a][i].Item2]=true;
				sb.Append(a.ToString()+" "+li[a][i].Item1.ToString()+"\n");
				h[a]++;
			}
		}
	}
}

public class Sc{
	public int I{get{return int.Parse(Console.ReadLine());}}
	public long L{get{return long.Parse(Console.ReadLine());}}
	public double D{get{return double.Parse(Console.ReadLine());}}
	public string S{get{return Console.ReadLine();}}
	public int[] Ia{get{return Array.ConvertAll(Console.ReadLine().Split(),int.Parse);}}
	public long[] La{get{return Array.ConvertAll(Console.ReadLine().Split(),long.Parse);}}
	public double[] Da{get{return Array.ConvertAll(Console.ReadLine().Split(),double.Parse);}}
	public string[] Sa{get{return Console.ReadLine().Split();}}
	public object[] Oa{get{return Console.ReadLine().Split();}}
	public int[] Ia2{get{return Array.ConvertAll(("0 "+Console.ReadLine()+" 0").Split(),int.Parse);}}
	public int[] Ia3(int a){return Array.ConvertAll((a.ToString()+" "+Console.ReadLine()).Split(),int.Parse);}
	public int[] Ia3(bool a,int b,bool c,int d){return Array.ConvertAll(((a?b.ToString()+" ":"")+Console.ReadLine()+(c?" "+d.ToString():"")).Split(),int.Parse);}
	public long[] La2{get{return Array.ConvertAll(("0 "+Console.ReadLine()+" 0").Split(),long.Parse);}}
	public long[] La3(int a){return Array.ConvertAll((a.ToString()+" "+Console.ReadLine()).Split(),long.Parse);}
	public long[] La3(bool a,int b,bool c,int d){return Array.ConvertAll(((a?b.ToString()+" ":"")+Console.ReadLine()+(c?" "+d.ToString():"")).Split(),long.Parse);}
	public T[] Arr<T>(int n,Func<T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f();}return a;}
	public T[] Arr<T>(int n,Func<int,T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(i);}return a;}
	public T[] Arr<T>(int n,Func<string[],T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(Console.ReadLine().Split());}return a;}
	public T[] Arr<T>(int n,Func<int,string[],T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(i,Console.ReadLine().Split());}return a;}
}


Measured memory_bytes: 51116