N,M,P,Q = map(int,input().split())

q = M // P
r = M % P

for _ in range(Q):
    x,f = map(int,input().split())
    y = f * pow(x,P-2,P) % P

    if y == 0:
        print(q)
        continue
    if y <= r:
        print(q+1)
    else:
        print(q)