N, M, P, Q = map(int, input().split())
querys = [list(map(int, input().split())) for _ in range(Q)]

for x, f in querys:
    count = 0
    answer = M // P
    tmp = M % P
    now = x
    while tmp >= count and f != 0:
        if (f-now) % x == 0:
            if ((f-now)//x + 1) + count <= tmp:
                answer += 1
            break
        count += (P-now)//x + 1
        now = (x - (P-now)%x) % x
    print(answer)