#include <algorithm>
#include <bitset>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <ctime>
#include <climits>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <utility>
#include <vector>
#define ALL(A)		(A).begin(),(A).end()
#define DUMP(A)    cout<<#A<<"="<<(A)<< endl
#define SIZE(A)    (int)((A).size())
#define P2(A)   ((A)*(A))
using namespace std;
typedef long long ll;

int main(){
    int n;
    for(;;){
        scanf("%d\n",&n);
        if(n==0) break;
        vector<double> xs(n),ys(n);
        for(int i=0;i<n;i++){
            scanf("%lf %lf\n",&xs[i],&ys[i]);
        }
        if(n==1){
            printf("1\n");
            continue;
        }
        int ma=1;
        for(int i=0;i<n;i++){
            for(int j=i+1;j<n;j++){
                double mx=(xs[i]+xs[j])/2,my=(ys[i]+ys[j])/2,vlen=sqrt(P2(xs[i]-xs[j])+P2(ys[i]-ys[j])),llen=sqrt(1-(P2(xs[i]-mx)+P2(ys[i]-my)));
                if(vlen>=2.00005) continue;
                double p1x=mx+(ys[i]-ys[j])*(llen/vlen),p1y=my-(xs[i]-xs[j])*(llen/vlen);
                double p2x=mx-(ys[i]-ys[j])*(llen/vlen),p2y=my+(xs[i]-xs[j])*(llen/vlen);
                int now1=0,now2=0;
                for(int k=0;k<n;k++){
                    if(P2(xs[k]-p1x)+P2(ys[k]-p1y)<=1.00005) now1++;
                    if(P2(xs[k]-p2x)+P2(ys[k]-p2y)<=1.00005) now2++;
                }
                ma=max(now1,ma);
                ma=max(now2,ma);
            }
        }
        printf("%d\n",ma);
    }
}