using System.Numerics;
using System;

public class Hello
{
    static void Main()
    {
        string[] line = Console.ReadLine().Trim().Split(' ');
        var n = int.Parse(line[0]);
        var m = int.Parse(line[1]);
        var p = int.Parse(line[2]);
        var q = int.Parse(line[3]);
        getAns(n, m, p, q);
    }
    static int ModInv(int a, int m) => (int)BigInteger.ModPow(a, m - 2, m);
    static void getAns(int n, int m, int p, int q)
    {
        for (int i = 0; i < q; i++)
        {
            string[] line = Console.ReadLine().Trim().Split(' ');
            var x = int.Parse(line[0]);
            var f = int.Parse(line[1]);
            if (x == 0) { Console.WriteLine(f == 0 ? m : 0); return; }
            var ww = f * ModInv(x, p);
            ww %= p;
            if (ww == 0) Console.WriteLine(m / p);
            else
            {
                if (m < ww) { Console.WriteLine(0); return; }
                var ans = (m - ww) / p + 1;
                Console.WriteLine(ans);
            }
        }
    }
}