import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.InputMismatchException;
import java.util.NoSuchElementException;

public class Main {

	public static void main(String[] args) {
		IO io = new IO();
		while(true) {
			int n = io.nextInt();
			if (n == 0) {
				break;
			}
			Vector2[] v = new Vector2[n];
			for(int i=0;i<n;i++) {
				v[i] = new Vector2(io.nextDouble(),io.nextDouble());
			}
			int ans = 1;
			for(int i=0;i<n;i++) {
				for(int j=i+1;j<n;j++) {
					Vector2 x = v[i].subtract(v[j]);
					double d = x.norm();
					double l = Math.sqrt(1 - Math.pow(d / 2, 2));
					Vector2 m = v[i].add(v[j]).divide(2);
					Vector2 y = x.rotate90().normalize();
					for(int sign=1;sign>=-1;sign-=2) {
						Vector2 c = m.add(y.multiply(l * sign));
						int sum = 0;
						for(int k=0;k<n;k++) {
							if (c.dist(v[k]) < 1 + Vector2.EPS) {
								sum++;
							}
						}
						ans = Math.max(ans,sum);
					}
				}
			}
			io.println(ans);
		}
		io.flush();
	}

}

class Vector2 {
	public static double EPS = 1E-6;
	public double x;
	public double y;
	public Vector2(double x,double y) {
		this.x = x;
		this.y = y;
	}
	public double dot(Vector2 v) {
		return this.x*v.x+this.y*v.y;
	}
	public double cross(Vector2 v) {
		return this.x*v.y-this.y*v.x;
	}
	public double norm() {
		return Math.sqrt(this.x*this.x+this.y*this.y);
	}
	public Vector2 normalize() {
		return divide(norm());
	}
	public Vector2 add(Vector2 v) {
		return new Vector2(x+v.x,y+v.y);
	}
	public Vector2 subtract(Vector2 v) {
		return new Vector2(x-v.x,y-v.y);
	}
	public Vector2 multiply(double k) {
		return new Vector2(x*k,y*k);
	}
	public Vector2 divide(double k) {
		return new Vector2(x/k,y/k);
	}
	public Vector2 rotate90() {
		return new Vector2(-y,x);
	}
	public Vector2 rotate270() {
		return new Vector2(y,-x);
	}
	public double dist(Vector2 v) {
		return this.subtract(v).norm();
	}
	public String toString() {
		return "(" + this.x + "," + this.y + ")";
	}
}
class IO extends PrintWriter {
	private final InputStream in;
	private final byte[] buffer = new byte[1024];
	private int ptr = 0;
	private int buflen = 0;

	public IO() { this(System.in);}
	public IO(InputStream source) { super(System.out); this.in = source;}
	private boolean hasNextByte() {
		if (ptr < buflen) {
			return true;
		}else{
			ptr = 0;
			try {
				buflen = in.read(buffer);
			} catch (IOException e) {
				e.printStackTrace();
			}
			if (buflen <= 0) {
				return false;
			}
		}
		return true;
	}
	private int readByte() { if (hasNextByte()) return buffer[ptr++]; else return -1;}
	private static boolean isPrintableChar(int c) { return 33 <= c && c <= 126;}
	private static boolean isNewLine(int c) { return c == '\n' || c == '\r';}
	public boolean hasNext() { while(hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++; return hasNextByte();}
	public boolean hasNextLine() { while(hasNextByte() && isNewLine(buffer[ptr])) ptr++; return hasNextByte();}
	public String next() {
		if (!hasNext()) {
			throw new NoSuchElementException();
		}
		StringBuilder sb = new StringBuilder();
		int b = readByte();
		while(isPrintableChar(b)) {
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	}
	public char[] nextCharArray(int len) {
		if (!hasNext()) {
			throw new NoSuchElementException();
		}
		char[] s = new char[len];
		int i = 0;
		int b = readByte();
		while(isPrintableChar(b)) {
			if (i == len) {
				throw new InputMismatchException();
			}
			s[i++] = (char) b;
			b = readByte();
		}
		return s;
	}
	public String nextLine() {
		if (!hasNextLine()) {
			throw new NoSuchElementException();
		}
		StringBuilder sb = new StringBuilder();
		int b = readByte();
		while(!isNewLine(b)) {
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	}
	public long nextLong() {
		if (!hasNext()) {
			throw new NoSuchElementException();
		}
		long n = 0;
		boolean minus = false;
		int b = readByte();
		if (b == '-') {
			minus = true;
			b = readByte();
		}
		if (b < '0' || '9' < b) {
			throw new NumberFormatException();
		}
		while(true){
			if ('0' <= b && b <= '9') {
				n *= 10;
				n += b - '0';
			}else if(b == -1 || !isPrintableChar(b)){
				return minus ? -n : n;
			}else{
				throw new NumberFormatException();
			}
			b = readByte();
		}
	}
	public int nextInt() {
		long nl = nextLong();
		if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE) {
			throw new NumberFormatException();
		}
		return (int) nl;
	}
	public char nextChar() {
		if (!hasNext()) {
			throw new NoSuchElementException();
		}
		return (char) readByte();
	}
	public double nextDouble() { return Double.parseDouble(next());}
	public int[] nextIntArray(int n) { int[] a = new int[n]; for(int i=0;i<n;i++) a[i] = nextInt(); return a;}
	public long[] nextLongArray(int n) { long[] a = new long[n]; for(int i=0;i<n;i++) a[i] = nextLong(); return a;}
	public double[] nextDoubleArray(int n) { double[] a = new double[n]; for(int i=0;i<n;i++) a[i] = nextDouble(); return a;}
	public void nextIntArrays(int[]... a) { for(int i=0;i<a[0].length;i++) for(int j=0;j<a.length;j++) a[j][i] = nextInt();}
	public int[][] nextIntMatrix(int n,int m) { int[][] a = new int[n][]; for(int i=0;i<n;i++) a[i] = nextIntArray(m); return a;}
	public char[][] nextCharMap(int n,int m) { char[][] a = new char[n][]; for(int i=0;i<n;i++) a[i] = nextCharArray(m); return a;}
	public void close() { super.close(); try {in.close();} catch (IOException e) {}}
}

Measured memory_bytes: 59248