t = int(input())
for case_ in range(0,t):
    n = int(input())
    if bin(n).count("1") == 1:
        print(-1)
    else:
        n2 = n
        n = bin(n)[::-1][:-2]
        temp = n[n.index("1") + 1:].index("1") + n.index("1") + 1
        print((1 << (temp + 1)) - (n2 & ((1 << (temp + 1)) - 1)))