import sys
input = sys.stdin.readline
T = int(input())
N = [int(input()) for _ in range(T)]
for n in N:
    c = n.bit_count()
    if c==1:
        print(-1)
        continue
    m = list("0" + bin(n)[2:])
    cnt = 0
    for i in range(len(m)-1, -1, -1):
        if m[i]=="1":
            cnt+=1
        else:
            if cnt>=2:
                m[i] = "1"
                for j in range(i+1, len(m)):
                    m[j] = "0"
                break
    m = int("".join(m), 2)
    x = m-n
    print(x)