def pop_count(n):
    c = (n & 0x5555555555555555) + ((n >> 1) & 0x5555555555555555)
    c = (c & 0x3333333333333333) + ((c >> 2) & 0x3333333333333333)
    c = (c & 0x0f0f0f0f0f0f0f0f) + ((c >> 4) & 0x0f0f0f0f0f0f0f0f)
    c = (c & 0x00ff00ff00ff00ff) + ((c >> 8) & 0x00ff00ff00ff00ff)
    c = (c & 0x0000ffff0000ffff) + ((c >> 16) & 0x0000ffff0000ffff)
    c = (c & 0x00000000ffffffff) + ((c >> 32) & 0x00000000ffffffff)
    return c

T = int(input())
for _ in range(T):
    N = int(input())
    pc = pop_count(N)
    if pc == 1:
        print(-1)
        continue
    ans = 0
    for i in range(32):
        if N >> i & 1:
            N += 1 << i
            ans += 1 << i
            if pop_count(N) < pc:
                break
    print(ans)