Red Huang

//====================================================================||  
//                        名稱  : Critical Wave.cpp                             ||  
//                     日期 : 2013年5月31日 11:15:07 PM                         ||  
//                         作者 : GCA                               ||  
//                  6AE7EE02212D47DAD26C32C0FE829006                  ||  
//====================================================================||  
#include <iostream>  
#include <cstdio>  
#include <cstring>  
#include <algorithm>  
#include <cmath>  
#include <climits>  
#include <vector>  
#include <set>  
#include <map>  
#include <queue>  
#include <cctype>  
#include <utility>  
using namespace std;  
#ifdef ONLINE\_JUDGE  
#define ll "%lld"  
#else  
#define ll "%I64d"  
#endif  
typedef unsigned int uint;  
typedef long long int Int;  
#define Set(a,s) memset(a,s,sizeof(a))  
#define Write(w) freopen(w,"w",stdout)  
#define Read(r) freopen(r,"r",stdin)  
#define Pln() printf("\\n")  
#define I\_de(x,n)for(int i=0;i<n;i++)printf("%d ",x\[i\]);Pln()  
#define De(x)printf(#x"%d\\n",x)  
#define For(i,x)for(int i=0;i<x;i++)  
#define CON(x,y) x##y  
#define Pmz(dp,nx,ny)for(int hty=0;hty<ny;hty++){for(int htx=0;htx<nx;htx++){\\  
    printf("%d ",dp\[htx\]\[hty\]);}Pln();}  
#define M 55  
#define PII pair<int,int\>  
#define PB push\_back  
#define oo INT\_MAX  
#define Set\_oo 0x3f  
#define Is\_debug true  
#define debug(...) if(Is\_debug)printf("DEBUG: "),printf(\_\_VA\_ARGS\_\_)  
#define FOR(it,c) for(\_\_typeof((c).begin()) it=(c).begin();it!=(c).end();it++)  
#define eps 1e-6  
bool xdy(double x,double y){return x>y+eps;}  
bool xddy(double x,double y){return x>y-eps;}  
bool xcy(double x,double y){return x<y-eps;}  
bool xcdy(double x,double y){return x<y+eps;}  
int min3(int x,int y,int z){  
    int tmp=min(x,y);  
    return min(tmp,z);  
}  
int max3(int x,int y,int z){  
    int tmp=max(x,y);  
    return max(tmp,z);  
}  
int n;  
struct point{  
    int x,y;  
}a\[1005\],b\[1005\];  
bool cmpx(point a,point b){  
    return a.x<b.x;  
}  
bool cmpy(point a,point b){  
    return a.y<b.y;  
}  
int main() {  
//    ios\_base::sync\_with\_stdio(0);  
  
    freopen("input.txt","r",stdin);  
    while(~scanf("%d",&n)){  
        for(int i=0;i<n;i++){  
            scanf("%d %d",&a\[i\].x,&a\[i\].y);  
            b\[i\].x=a\[i\].x;  
            b\[i\].y=a\[i\].y;  
        }  
//        debug("%d\\n",n);  
        sort(a,a+n,cmpy);  
        sort(b,b+n,cmpx);  
        int ans=0;  
        int j=0;  
        int tsans=0;  
        for(int i=0;i<n;i++){  
            if(i==0||a\[i\].y!=a\[i-1\].y){  
                int y=a\[i\].y;  
                int next=2;  
                for(j=0,tsans=0;;){  
                    b\[n\].y=y;  
                    while(b\[j\].y!=y)j++;  
//                    printf("%d\\n",j);  
                    if(j>=n)break;  
                    int tmp=b\[j\].x;  
                    b\[n\].x=tmp+1;  
                    while(b\[j\].x==tmp)j++;  
                    tsans++;  
                    y+=next;  
                    next=-next;  
                }  
                ans=max(ans,tsans);  
                next=-2;  
                y=a\[i\].y;  
                for(j=0,tsans=0;;){  
                    b\[n\].y=y;  
                    while(b\[j\].y!=y)j++;  
//                    printf("%d\\n",j);  
                    if(j>=n)break;  
                    int tmp=b\[j\].x;  
                    b\[n\].x=tmp+1;  
                    while(b\[j\].x==tmp)j++;  
                    tsans++;  
                    y+=next;  
                    next=-next;  
                }  
                ans=max(ans,tsans);  
            }  
  
        }  
        printf("%d\\n",ans);  
    }  
  
  
  
  
  
  
  
  
  
}