from math import isqrt
for _ in range(int(input())):
    n = int(input())
    if n == 0:
        print(0)
        continue
    s = isqrt(n) - 1
    for _ in range(3):
        s2 = s * s
        rest = n ^ s ^ s2
        ans = s2 ^ rest
        if s2 <= ans <= s2 + 2 * s:
            # ok += 1
            print(ans)
            break
        s += 1
    else:
        print(-1)
# M = 100000
# ok = 0
# for n in range(1, M):
#     s = isqrt(n) - 1
#     for _ in range(3):
#         s2 = s * s
#         rest = n ^ s ^ s2
#         ans = s2 ^ rest
#         if s2 <= ans <= s2 + 2 * s:
#             ok += 1
#             break
#         s += 1
#     # else:
#     #     print(n)
# print(ok)

# # ok = 0
# # for n in range(1, M):
# #     for k in range(10 * n + 1):
# #         sk = isqrt(k)
# #         if k ^ sk == n:
# #             # print(n, k)
# #             ok += 1
# #             break
# # print(ok)