import math

T = int(input())
for _ in range(T):
    N = int(input())
    t = N // pow(2, 30)

    ans = -1
    for m in range(int(math.sqrt(t * pow(2, 30))), 
                   int(math.sqrt((t + 1) * pow(2, 30)))): 
        # print(m)
        if m ** 2 <= m ^ N < (m + 1) ** 2:
            ans = m ^ N

    print(ans)