def main():
    N, M, P, Q = map(int, input().split())
    for i in range(Q):
        x, f = map(int, input().split())
        if x % P == 0:
            print(M if f == 0 else 0)
        else:
            z = pow(x, -1, P) * f % P
            if z == 0:
                z = P
            print((M - z + P) // P)


if __name__ == '__main__':
    main()