#include <iostream>
#include <fstream>
#include <deque>

using namespace std;
ifstream fin("diagonala.in");
ofstream fout("diagonala.out");

const int nmx=200005;
int n,i,j,p,nr,rez,x1,x2,n1,n2;

struct Seg
{	int x,y;	} filn[nmx],ln[nmx],qmx[nmx],qmn[nmx];

void add(Seg a,int id)
{
	while(x1<=x2 && qmx[x2].x<a.x)
		x2--;
	qmx[++x2]={a.x, id};

	while(n1<=n2 && qmn[n2].x>a.y)
		n2--;
	qmn[++n2]={a.y, id};
}
void erase(int id)
{
	if(x1<=x2 && qmx[x1].y==id)
		x1++;
	if(n1<=n2 && qmn[n1].y==id)
		n1++;
}

void solve()
{
	x1=n1=1;
	x2=n2=0;
	p=1;
	add(ln[1],1);
	for(i=2;i<=n;i++)
	{
		add(ln[i], i);
		while(p<i && qmx[x1].x>qmn[n1].x)
		{
			erase(p);
			p++;
		}
		rez=max(rez, i-p+1);
	}
}

int main() {

	fin>>n;
	for(i=1;i<=n;i++)
		fin>>filn[i].x>>filn[i].y;

	rez=1;

	for(i=1;i<=n;i++)
		ln[i]={filn[i].x+(i-1), filn[i].y+(i-1)};

	solve();

	for(i=n;i>=1;i--)
		ln[i]={filn[i].x+(n-i), filn[i].y+(n-i)};

	solve();

	fout<<rez<<"\n";
}