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


#define li          long long int
#define rep(i,to)   for(li i=0;i<((li)(to));i++)
#define repp(i,start,to)    for(li i=(li)(start);i<((li)(to));i++)
#define pb          push_back
#define sz(v)       ((li)(v).size())
#define bgn(v)      ((v).begin())
#define eend(v)     ((v).end())
#define allof(v)    (v).begin(), (v).end()
#define dodp(v,n)       memset(v,(li)n,sizeof(v))
#define bit(n)      (1ll<<(li)(n))
#define mp(a,b)     make_pair(a,b)
#define rin rep(i,n)
#define EPS 1e-12
#define ETOL 1e-8
#define MOD 1000000007ll
typedef pair<li, li> PI;

#define INF bit(60)

#define DBGP 1


#define idp if(DBGP)
#define F first
#define S second
#define p2(a,b)     idp cout<<a<<"\t"<<b<<endl
#define p3(a,b,c)       idp cout<<a<<"\t"<<b<<"\t"<<c<<endl
#define p4(a,b,c,d)     idp cout<<a<<"\t"<<b<<"\t"<<c<<"\t"<<d<<endl
#define p5(a,b,c,d,e)       idp cout<<a<<"\t"<<b<<"\t"<<c<<"\t"<<d<<"\t"<<e<<endl
#define p6(a,b,c,d,e,f)     idp cout<<a<<"\t"<<b<<"\t"<<c<<"\t"<<d<<"\t"<<e<<"\t"<<f<<endl
#define p7(a,b,c,d,e,f,g)       idp cout<<a<<"\t"<<b<<"\t"<<c<<"\t"<<d<<"\t"<<e<<"\t"<<f<<"\t"<<g<<endl
#define p8(a,b,c,d,e,f,g,h)     idp cout<<a<<"\t"<<b<<"\t"<<c<<"\t"<<d<<"\t"<<e<<"\t"<<f<<"\t"<<g<<"\t"<<h<<endl
#define p9(a,b,c,d,e,f,g,h,i)       idp cout<<a<<"\t"<<b<<"\t"<<c<<"\t"<<d<<"\t"<<e<<"\t"<<f<<"\t"<<g<<"\t"<<h<<"\t"<<i<<endl
#define p10(a,b,c,d,e,f,g,h,i,j)        idp cout<<a<<"\t"<<b<<"\t"<<c<<"\t"<<d<<"\t"<<e<<"\t"<<f<<"\t"<<g<<"\t"<<h<<"\t"<<i<<"\t"<<j<<endl
#define foreach(it,v)   for(__typeof((v).begin()) it=(v).begin(); it!=(v).end(); ++it)
#define p2p(x)      idp p2((x).F, (x).S)
#define dump(x,n)   idp{rep(i,n){cout<<x[i]<<" ";}puts("");}
#define dump2(x,n)  idp{rep(i,n){cout<<"["<<x[i].F<<" , "<<x[i].S<<"] ";}puts("");}
#define dumpi(x)    idp{foreach(it, x){cout<<(*it)<<" ";}puts("");}
#define dumpi2(x)   idp{foreach(it, x){cout<<"["<<(it)->F<<" , "<<(it)->S<<"] ";}puts("");}

#define read2d(a,w,h)   rep(i,h)rep(j,w)cin>>a[i][j]
#define dump2d(a,w,h)   rep(i,h){rep(j,w)cout<<a[i][j]<<" ";puts("");}

typedef pair<li, li> PI;

set<li> edges[100100];
li parent[100100];
vector<PI> res;
li degree[100100];
vector<vector<li>> child;

inline void dfs1(li now, li from) {
    parent[now] = from;
    for (auto && next : edges[now]) {
        if (next == from) {
            continue;
        }
        if (parent[next] != -2) {
            continue;
        }
        dfs1(next, now);
    }
}

inline void dfs2(li now, li from) {
    for (auto && next : child[now]) {
        dfs2(next, now);
    }
    if (from < 0) {
        return;
    }
    if (degree[now] % 2 == 0) {
        res.pb({from + 1, now + 1});
        degree[from]++;
    } else {
        res.pb({now + 1, from + 1});
        degree[now]++;
    }
}

int main() {
    li n, m;
    cin >> n >> m;
    rep(i, m) {
        li a, b;
        cin >> a >> b;
        a--;
        b--;
        edges[a].insert(b);
        edges[b].insert(a);
    }
    if (m % 2 > 0) {
        puts("-1");
        return 0;
    }

    rin{
        parent[i] = -2;
    }
    dfs1(0, -1);

    rep(i, n) {
        for (auto && next : edges[i]) {
            if (next > i) {
                continue;
            }
            if (parent[i] == next || parent[next] == i) {
                continue;
            }
            //p3(":", i, next);
            res.pb({i + 1, next + 1});
            degree[i]++;
        }
    }

    //dump(parent, n);

    child.resize(n);
    rin{
        if (parent[i] >= 0) {
            child[parent[i]].pb(i);
        }
    }

    // dfs
    dfs2(0, -1);
    for (auto && p : res) {
        cout << p.F << " " << p.S << endl;
    }


    return 0;
}


Measured memory_bytes: 27760