from itertools import count

LIMIT = 10**9


def f(n: int) -> list[str]:
    s = ''.join(sorted(str(n)))
    res = [s]
    while len(s) > 1 and s[0] == '0':
        s = s[1:]
        res.append(s)

    return res


d = {}
for i in count(1):
    x = i*i
    if x > LIMIT: break

    for y in f(x):
        if y not in d:
            d[y] = x


def solve():
    N = int(input())
    ans = INF
    for y in f(N):
        if y in d:
            a = ''.join(sorted(str(N)))
            b = ''.join(sorted(str(d[y])))
            if len(a) >= len(b) and a.endswith(b):
                ans = min(ans, d[y])

    if ans == INF:
        return -1
    return ans


INF = 1 << 60
T = int(input())
for _ in range(T):
    res = solve()
    print(res)