#include <iostream> #include<algorithm> using namespace std; long p[10010][10010]; int main(){ int n; cin>>n; long a[n],b[n],am=0,bm=0; for(int i=0;i<n;i++){ cin>>a[i]>>b[i]; if(a[i]>am) am=a[i]; if(b[i]>bm) bm=b[i]; p[a[i]][b[i]]++; } for(int i=0;i<=am;i++){ for(int j=0;j<=bm;j++){ if(p[i][j]!=0) cout<<i<<" "<<j<<endl; } } return 0; }