#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vii;
typedef pair<int,int> pi;
typedef vector<pi> pii;
typedef tuple<int,int,int> ti;
typedef vector<ll> li;
typedef vector<li> lii;
#define REP(i,a,b) for(int i=a;i<b;i++)
#define F first
#define S second
#define PB push_back
#define LSOne(s) ((s)&(-s))
#define all(x) (x).begin(),(x).end()
ll INF=1000000000000000010;
int inf=1e9+10;
ll M=1e9+7;
int main(){
ios::sync_with_stdio(0);
cin.tie(0);
int n,s,t;cin>>n>>s>>t;
vector<set<pi>> a(t+1);
vector<pi> ans(n);
REP(i,0,n){
int x,y;cin>>x>>y;
if(x==y){
ans[i]={x,y};
continue;
}
a[x].insert({y,i});
a[y].insert({x,i});
}
REP(i,1,t+1){
if(a[i].empty())continue;
int p=1;
while(!a[i].empty()){
p=1-p;
set<int> st;
vi arr;
int x=i;
bool f=1;
while(f){
if(a[x].empty())break;
st.insert(x);arr.PB(x);
auto [y,z]=*a[x].begin();
if(p%2==0)ans[z]={x,y};
else ans[z]={y,x};
a[x].erase({y,z});
a[y].erase({x,z});
if(st.count(y)){
while(arr.back()!=y){
st.erase(arr.back());
arr.pop_back();
}
st.erase(arr.back());
arr.pop_back();
if(arr.empty())break;
}
x=y;
}
}
}
for(auto [u,v]:ans)cout<<u<<" "<<v<<"\n";
}
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