n,m,p,q = map(int, input().split())

for _ in range(q):
  x,f = map(int, input().split())
  
  if(x%p==0):
    if(f==0):
      print(m)
    else:
      print(0)
    continue
  
  a = f*pow(x, -1, p)
  a%=p
  
  
  ans = m//p
  
  if(a!=0 and m%p >= a):
    ans+=1
    
  print(ans)