n, m, p, q = map(int, input().split())
c, r = divmod(m, p)
for _ in range(q):
    x, f = map(int, input().split())
    y = f * pow(x, p - 2, p) % p
    if y <= r:
        ans = c + 1
    else:
        ans = c
    if y == 0:
        ans = max(ans - 1, 0)
    print(ans)