import sys
input = sys.stdin.readline

T=int(input())
for tests in range(T):
    N=int(input())

    k=N.bit_length()

    L=0
    for i in range(k):
        if i>=k-k//2:
            if N & (1<<i) != 0:
                L+=(1<<i)

    R=L+(1<<(k-k//2))
    x=int(L**0.5)

    ANS=-1

    for i in range(x,x+10**9):
        rest=N^i

        if i*i<=rest<(i+1)*(i+1):
            ANS=rest
            break

        if i*i>R:
            break

    print(ANS)