p.m=Max{
	p.left.m; //最大前缀和的尾元素在左子树
	p.left.s+p.w; //最大前缀和的尾元素就是p
	p.left.s+p.w+p.right.m; //最大前缀和的尾元素在右子树
}

/* 
 * Problem: POI2001 kop
 * Author: Guo Jiabao
 * Time: 2009.2.7 16:16
 * State: Solved
*/
#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>

using namespace std;

const int MAXN=15001;
struct point{int x,y;};
struct linknode{int s;linknode *next;};
class Treap_node
{
	public:
		Treap_node *left,*right;
		int fix,weight,sum,m,key;
		Treap_node(int tk,int w):key(tk),weight(w),sum(w),m(w){fix=rand();left=right=0;}
		inline int leftsum (){return left ?left ->sum:0;}
		inline int rightsum(){return right?right->sum:0;}
};

int H,W;//区域高度 宽度
int N,L,Lc=-1,MaxAns;
int D[MAXN];
point P[MAXN];
linknode LS[MAXN],*Line[MAXN];
Treap_node *Treap_root;

void Treap_Rotate_Right(Treap_node *&p)
{
	Treap_node *q=p->left;
	q->sum+=p->rightsum()+p->weight;
	p->sum=q->rightsum()+p->rightsum()+p->weight;
	p->left=q->right;
	q->right=p;
	p=q;
}

void Treap_Rotate_Left(Treap_node *&p)
{
	Treap_node *q=p->right;
	q->sum+=p->leftsum()+p->weight;
	p->sum=q->leftsum()+p->leftsum()+p->weight;
	p->right=q->left;
	q->left=p;
	p=q;
}

void Treap_maintain(Treap_node *&p)
{
	int lm,ls,rm;
	lm=ls=rm=0;
	if (p->left)
		lm=p->left->m,ls=p->left->sum;
	if (p->right)
		rm=p->right->m;
	p->m=lm;
	if (ls + p->weight > p->m)	p->m = ls + p->weight;
	if (ls + p->weight + rm > p->m) p->m=ls + p->weight + rm;
}

void Treap_edit(Treap_node *&p,int v,int delta)
{
	if (!p)
		p=new Treap_node(v,delta);
	else
	{
		if ( v < p->key )
		{
			p->sum+=delta;
			Treap_edit(p->left,v,delta);
			if (p->left && p->left->fix < p->fix)
			{
				Treap_Rotate_Right(p);
				Treap_maintain(p->right);
			}
			Treap_maintain(p);
		}
		else if ( v > p->key )
		{
			p->sum+=delta;
			Treap_edit(p->right,v,delta);
			if (p->right && p->right->fix < p->fix)
			{
				Treap_Rotate_Left(p);
				Treap_maintain(p->left);
			}
			Treap_maintain(p);
		}
		else
		{
			p->weight+=delta;
			p->sum+=delta;
			Treap_maintain(p);
		}
	}
}

void linktable_ins(linknode *&p,int v)
{
	if (p)
	{
		linknode *t=p;
		p=&LS[++Lc];
		p->next=t;
	}
	else
		p=&LS[++Lc];
	LS[Lc].s=v;
}

void init()
{
	freopen("kop.in","r",stdin);
	freopen("kop.out","w",stdout);
	scanf("%d%d%d",&W,&H,&N);
	for (int i=1;i<=N;i++)
		scanf("%d%d",&P[i].x,&P[i].y);
}

inline int cmp(const void *a,const void *b)
{
	return ((point *)a)->x - ((point *)b)->x;
}

void discrete() //离散化横坐标 建立链表
{
	int i,lastv=-1;
	qsort(P+1,N,sizeof(P[0]),cmp);
	L=0;
	for (i=1;i<=N;i++)
	{
		if (P[i].x!=lastv)
		{
			lastv=P[i].x;
			D[++L]=P[i].x;
			linktable_ins(Line[L],P[i].y);
		}
		else
			linktable_ins(Line[L],P[i].y);
	}
}

void RemoveLine(int p)
{
	for (linknode *k=Line[p];k;k=k->next)
	{
		Treap_edit(Treap_root,k->s,-1);
		Treap_edit(Treap_root,k->s+H+1,1);
	}
}

void AddLine(int p)
{
	for (linknode *k=Line[p];k;k=k->next)
	{
		Treap_edit(Treap_root,k->s,1);
		Treap_edit(Treap_root,k->s+H+1,-1);
	}
}


void scanx() //横向扫描 确定区间
{
	int Lb,Rb;
	AddLine(1);
	for (Lb=Rb=1;Rb<L && Lb<=L;)
	{
		while (Rb+1<=L && D[Rb+1]-D[Lb]<=W)
			AddLine(++Rb);
		if (Treap_root->m>MaxAns)
			MaxAns=Treap_root->m;
		RemoveLine(Lb++);
	}
}

void solve()
{
	discrete();
	scanx();
	printf("%d",MaxAns);
}

int main()
{
	init();
	solve();
	return 0;
}