import java.util.Scanner;

public class Main {
	public static void main (String[] args) {
		Scanner scanner = new Scanner(System.in);
		int l = scanner.nextInt();
		int n = scanner.nextInt();
		int k = scanner.nextInt();
		int count = 0;
		for(int i=0; i<n; i++) {
			int x1 = scanner.nextInt();
			int y1 = scanner.nextInt();
			int x2 = scanner.nextInt();
			int y2 = scanner.nextInt();
			if(x1*x1+y1*y1<=l*l||x2*x2+y2*y2<=l*l)
				count++;
			else {
			 	int a, b, c;
		    	int deltaX=x2-x1;
				int deltaY=y2-y1;
		    	a=deltaY;
		    	b=-deltaX;
		    	c=y1*deltaX-x1*deltaY;
		    	if(c*c<=l*l*(a*a+b*b)&&(-c*b<=(b*b+a*a)*Math.max(y2, y1)&&-c*b>=(b*b+a*a)*Math.min(y2, y1)))
		        	count++;
			}
		}
		System.out.println(count/k+1);
	}
}