package main

import . "fmt"
import . "math/big"
import . "os"
import bf "bufio"

func main() {
	rd:=bf.NewReader(Stdin)
	var n,m,p,q int64
	Fscan(rd,&n,&m,&p,&q)
	P:=NewInt(p)
	for ;q>0;q-- {
		var x,f int64
		Fscan(rd,&x,&f)
		X:=NewInt(x)
		F:=NewInt(f)
		X.ModInverse(X,P)
		F.Mul(F,X).Mod(F,P)
		f=F.Int64()
		r:=m/p
		if f>0&& f<=m%p {
			r++
		}
		Println(r)
	}
}