T=int(input())
for _ in range(T):
	n=int(input())
	if n.bit_count()==1:
		print(-1)
		continue
	p=[]
	for i in range(30):
		if (n>>i)&1:
			p+=[i]
		if len(p)==2:
			break
	p1,p2=p
	print(int("1"*(p2-p1)+"0"*p1,2))