#include <bits/stdc++.h> using namespace std; const int Maxn=5010; struct Node( int x,y; ); Node a[Maxn]; bool cmp(const Node &t1,const Node &t2){ return t1.x<t2.x; } int n,cnt=0,last=0; int main() { cin>>n; for(int i=1; i<=n;i++){ cout<<a[i].x<<a[i].y<<endl; } last=a[1].y; cnt=1; for(int i=2;i<=n;i++){ if (a[i].x<=last){ last=max(last,a[i].y); }else{ a[cnt].y=last; cin+=1; a[cnt].x=a[i].x; last=a[i].y } } a[cnt].y=last; cout<<cnt<<endl; for(int i=1;i<=cnt.i++){ cout<<a[i],x<<" "<<a[i].y<<endl; } return 0; }