#include<bits/stdc++.h>
#define rep(i,a,b) for(int i=(a);i<=(b);i++)
#define per(i,a,b) for(int i=(a);i>=(b);i--)
#define fi first
#define se second
#define eb emplace_back
#define popc __builtin_popcount
#define clz __builtin_clz
#define ctz __builtin_ctz
using namespace std;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<pii> vp;
typedef long double ld;
typedef unsigned long long ull;
typedef long long i64;
typedef __int128 i128;

int read() {
  int x=0,w=1; char c=getchar(); 
  while(!isdigit(c)) {if(c=='-') w=-1; c=getchar();}
  while(isdigit(c)) {x=x*10+(c-'0'); c=getchar();}
  return x*w;
}

const int N=3e6+9;
int n,K,l[N],r[N],d[N],u[N],bx[N],by[N],cx,cy;
vp ans;

namespace Sol1 {
  bool vst[N];
  vi cov(int x,int y) {
    vi tmp;
    rep(i,1,n) if(!vst[i]) {
      if(l[i]<=x&&x<=r[i]&&d[i]<=y&&y<=u[i])
        tmp.eb(i);
    }
    return tmp;
  }
  void dfs(int pos,vp ps) {
    if(pos==K+1) {
      rep(i,1,n) if(!vst[i]) return;
      ans=ps; return;
    }
    int maxl=0, minr=cx+1, maxd=0, minu=cy+1;
    rep(i,1,n) if(!vst[i])
      maxl=max(maxl,l[i]), minr=min(minr,r[i]),
      maxd=max(maxd,d[i]), minu=min(minu,u[i]);
    for(int x:{maxl,minr}) for(int y:{maxd,minu}) {
      vi f=cov(x,y); for(int i:f) vst[i]=1;
      vp q=ps; q.eb(x,y); dfs(pos+1,q);
      if(ans.size()) return; for(int i:f) vst[i]=0;
    }
  }
  void work() {vp tmp; dfs(1,tmp);}
}
namespace Sol2 {
  int tot,pre[4][N][2],dfn[N],low[N],scc[N],cnt,in[N],st[N],top,pos[4],tick;
  vi e[N];
  void add(int x,int y) {if(x&&y) e[x].eb(y);}
  void dfs(int u) {
    dfn[u]=low[u]=++tick, st[++top]=u, in[u]=1;
    for(int v:e[u])
      if(!dfn[v]) dfs(v), low[u]=min(low[u],low[v]);
      else if(in[v]) low[u]=min(low[u],dfn[v]);
    if(dfn[u]==low[u]) {
      ++cnt; do {
        int v=st[top]; scc[v]=cnt, in[v]=0;
      } while(st[top--]!=u);
    }
  }
  void work() {
    int maxl=0, minr=cx+1, maxd=0, minu=cy+1;
    rep(i,1,n)
      maxl=max(maxl,l[i]), minr=min(minr,r[i]),
      maxd=max(maxd,d[i]), minu=min(minu,u[i]);
    int L=min(maxl,minr), R=max(maxl,minr);
    int D=min(minu,maxd), U=max(minu,maxd);
    rep(t,0,3) {
      int x=(t<2?D:L), y=(t<2?U:R);
      rep(i,x,y) rep(j,0,1) pre[t][i][j]=++tot;
      rep(i,x+1,y) e[pre[t][i][0]].eb(pre[t][i-1][0]);
      rep(i,x,y-1) e[pre[t][i][1]].eb(pre[t][i+1][1]);
    }
    rep(i,1,n) {
      static int cov[4], x[4], y[4];
      cov[0]=(l[i]<=L&&L<=r[i]), x[0]=d[i], y[0]=u[i];
      cov[1]=(l[i]<=R&&R<=r[i]), x[1]=d[i], y[1]=u[i];
      cov[2]=(d[i]<=D&&D<=u[i]), x[2]=l[i], y[2]=r[i];
      cov[3]=(d[i]<=U&&U<=u[i]), x[3]=l[i], y[3]=r[i];
      int sum=0; rep(i,0,3) sum+=cov[i];
      if(sum==1) {
        rep(t,0,3) if(cov[t]) {
          add(pre[t][x[t]-1][1],pre[t][x[t]-1][0]);
          add(pre[t][y[t]][0],pre[t][y[t]][1]);
        }
      } else if(sum==2) {
        if(cov[0]&&cov[2])
          add(pre[0][y[0]][0],pre[2][y[2]][1]),
          add(pre[2][y[2]][0],pre[0][y[0]][1]);
        else if(cov[0]&&cov[3])
          add(pre[0][x[0]-1][1],pre[3][y[3]][1]),
          add(pre[3][y[3]][0],pre[0][x[0]-1][0]);
        else if(cov[1]&&cov[2])
          add(pre[1][y[1]][0],pre[2][x[2]-1][0]),
          add(pre[2][x[2]-1][1],pre[1][y[1]][1]);
        else if(cov[1]&&cov[3])
          add(pre[1][x[1]-1][1],pre[3][x[3]-1][0]),
          add(pre[3][x[3]-1][1],pre[1][x[1]-1][0]);
        else {
          int p=cov[0]?0:2;
          rep(t,p,p+1) {
            add(pre[t][y[t]][0],pre[t^1][y[t^1]][1]),
            add(pre[t][y[t]][0],pre[t^1][x[t^1]-1][0]),
            add(pre[t][x[t^1]-1][1],pre[t^1][y[t^1]][1]),
            add(pre[t][x[t^1]-1][1],pre[t^1][x[t^1]-1][0]);
          }
        }  
      }
    }
    rep(i,1,tot) if(!dfn[i]) dfs(i);
    rep(t,0,3) {
      int x=(t<2?D:L), y=(t<2?U:R);
      rep(i,x,y)
        if(scc[pre[t][i][1]]<scc[pre[t][i][0]])
          {pos[t]=i; break;}
    }
    ans.eb(L,pos[0]), ans.eb(R,pos[1]);
    ans.eb(pos[2],D), ans.eb(pos[3],U);
  }
}

signed main() {
  n=read(), K=read();
  rep(i,1,n) l[i]=read(), d[i]=read(), r[i]=read(), u[i]=read();
  rep(i,1,n) bx[++cx]=l[i], bx[++cx]=r[i];
  rep(i,1,n) by[++cy]=d[i], by[++cy]=u[i];
  sort(bx+1,bx+cx+1); cx=unique(bx+1,bx+cx+1)-bx-1;
  sort(by+1,by+cy+1); cy=unique(by+1,by+cy+1)-by-1;
  rep(i,1,n) l[i]=lower_bound(bx+1,bx+cx+1,l[i])-bx;
  rep(i,1,n) r[i]=lower_bound(bx+1,bx+cx+1,r[i])-bx;
  rep(i,1,n) d[i]=lower_bound(by+1,by+cy+1,d[i])-by;
  rep(i,1,n) u[i]=lower_bound(by+1,by+cy+1,u[i])-by;
  Sol1::work();
  if(!ans.size()) Sol2::work();
  for(auto [x,y]:ans) printf("%d %d\n",bx[x],by[y]);
  checker();
  return 0;
}

answer.code: In function ‘int main()’:
answer.code:147:3: error: ‘checker’ was not declared in this scope
  147 |   checker();
      |   ^~~~~~~