#include <iostream>
using namespace std;
 
int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	int l, n, k, count=0;
	cin >> l >> n >> k;
	for(int i=0; i<n; i++)
	{
		int x1, y1, x2, y2;
		cin >> x1 >> y1 >> x2 >> y2;
		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)*max(y2, y1)&&-c*b>=(b*b+a*a)*min(y2, y1)))
				count++;
		}
	}
	cout << count/k+1 << endl; 
	return 0;
}

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MyA1IDQKMiA0IDUgNwoxIC0xIC0xIDEKOCAxMCAyIDcKMTIgMyA0IDIKMTAwIDEwMCAtMTAwIC0xMDAK

3 5 4
2 4 5 7
1 -1 -1 1
8 10 2 7
12 3 4 2
100 100 -100 -100