import java.awt.*;
import java.awt.geom.*;
import java.io.*;
import java.util.*;
class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] a = new int[n];
		int[] b = new int[n];
		int[] c = new int[n];
		int[] d = new int[n];
		
		for(int i = 0; i < n; i++) {
			a[i] = sc.nextInt();
			b[i] = sc.nextInt();
			c[i] = sc.nextInt();
			d[i] = sc.nextInt();
		}
		int max = 0;
		for(int i = 0; i < n; i++) {
			for(int j = 0; j < n; j++) {
				
				int ax = a[i];
				int bx = b[i];
				
				int cx = c[j];
				int dx = d[j];
				
				Line2D xL = new Line2D.Double(ax,bx,cx,dx);	
				Line2D xLB = new Line2D.Double(cx,dx,ax,bx);	
				int ay = a[j];
				int by = b[j];
				
				int cy = c[i];
				int dy = d[i];
				
				Line2D yL = new Line2D.Double(ay,by,cy,dy);
				Line2D yLB = new Line2D.Double(cy,dy,ay,by);
				
				int xSumA = 0;
				int ySumA = 0;
				
				int xSumB = 0;
				int ySumB = 0;
				
				int xSumAB = 0;
				int ySumAB = 0;
				
				int xSumBB = 0;
				int ySumBB = 0;
				
				int xSumA2 = 0;
				int ySumA2 = 0;
				
				int xSumB2 = 0;
				int ySumB2 = 0;
				
				int xSumAB2 = 0;
				int ySumAB2 = 0;
				
				int xSumBB2 = 0;
				int ySumBB2 = 0;
				

				for(int k = 0; k < n; k++) {
					Line2D target = new Line2D.Double(a[k],b[k],c[k],d[k]);
					Line2D target2 = new Line2D.Double(c[k],d[k],a[k],b[k]);
					if(target.intersectsLine(xL)) xSumA++;
					if(target.intersectsLine(yL)) ySumA++;
					if(xL.intersectsLine(target)) xSumB++;
					if(yL.intersectsLine(target)) ySumB++;
					if(target.intersectsLine(xLB)) xSumAB++;
					if(target.intersectsLine(yLB)) ySumAB++;
					if(xLB.intersectsLine(target)) xSumBB++;
					if(yLB.intersectsLine(target)) ySumBB++;
					
					if(target2.intersectsLine(xL)) xSumA2++;
					if(target2.intersectsLine(yL)) ySumA2++;
					if(xL.intersectsLine(target2)) xSumB2++;
					if(yL.intersectsLine(target2)) ySumB2++;
					if(target2.intersectsLine(xLB)) xSumAB2++;
					if(target2.intersectsLine(yLB)) ySumAB2++;
					if(xLB.intersectsLine(target2)) xSumBB2++;
					if(yLB.intersectsLine(target2)) ySumBB2++;
				}
				
				max = Math.max(xSumA, max);
				max = Math.max(ySumA, max);
				max = Math.max(xSumB, max);
				max = Math.max(ySumB, max);
				max = Math.max(xSumAB, max);
				max = Math.max(ySumAB, max);
				max = Math.max(xSumBB, max);
				max = Math.max(ySumBB, max);
				max = Math.max(xSumA2, max);
				max = Math.max(ySumA2, max);
				max = Math.max(xSumB2, max);
				max = Math.max(ySumB2, max);
				max = Math.max(xSumAB2, max);
				max = Math.max(ySumAB2, max);
				max = Math.max(xSumBB2, max);
				max = Math.max(ySumBB2, max);
				
			}
		}
		
		System.out.println(max);
		
		
		
		
	} 	
	
	
}