package main

import (
	"bufio"
	"fmt"
	"os"
)

func sq(x int64) int64 {
	return x * x
}

func main() {
	in := bufio.NewReader(os.Stdin)
	out := bufio.NewWriter(os.Stdout)
	defer out.Flush()

	var a, v, u int64
	var n int
	if _, err := fmt.Fscan(in, &a, &v, &u, &n); err != nil {
		return
	}

	vv := v * v
	uu := u * u
	A := vv - uu
	aa2 := a * a

	ans := 0
	for i := 0; i < n; i++ {
		var x, y int64
		fmt.Fscan(in, &x, &y)

		dx := a - x
		endpoint := vv*(sq(dx)+sq(y)) <= uu*aa2

		if A <= 0 {
			if endpoint {
				ans++
			}
		} else {
			if endpoint || (x >= 0 && vv*x <= A*a && uu*sq(x) >= A*sq(y)) {
				ans++
			}
		}
	}

	fmt.Fprintln(out, ans)
}