import bisect
import copy
import decimal
import fractions
import heapq
import itertools
import math
import random
import sys
import time
from collections import Counter,deque,defaultdict
from functools import lru_cache,reduce
from heapq import heappush,heappop,heapify,heappushpop,_heappop_max,_heapify_max
def _heappush_max(heap,item):
    heap.append(item)
    heapq._siftdown_max(heap, 0, len(heap)-1)
def _heappushpop_max(heap, item):
    if heap and item < heap[0]:
        item, heap[0] = heap[0], item
        heapq._siftup_max(heap, 0)
    return item
from math import gcd as GCD
read=sys.stdin.read
readline=sys.stdin.readline
readlines=sys.stdin.readlines
write=sys.stdout.write

N,M,P,Q=map(int,readline().split())
for q in range(Q):
    x,f=map(int,readline().split())
    if x%P==0:
        if f==0:
            ans=M
        else:
            ans=0
    else:
        y=pow(x,P-2,P)*f%P
        if y:
            ans=(M-y)//P+1
        else:
            ans=M//P
    print(ans)