n, m, p, q = map(int, input().split())
assert 1 <= n <= 10 ** 9
assert 1 <= m <= 10 ** 9
assert 2 <= p <= 10 ** 9
assert 1 <= q <= 10 ** 5
for _ in range(q):
  x, f = map(int, input().split())
  assert 1 <= x <= n
  assert 0 <= f <= p - 1
  if x % p == 0:
    print(0 if f else m)
    continue
  y = f * pow(x, p-2, p) % p
  print(m // p if y == 0 or y > m % p else m // p + 1)