# 10**9 までの平方数を洗い出す
pattern = {}
# pattern[(1, 0, 2, 3, 1, 3, ...)] = 平方数


for i in range(1, 10**5):
    x = i*i
    if x > 10**9:
        break

    cnt = [0] * 9 # 1 ~ 9 の個数
    for s in str(x):
        if s != '0':
            cnt[int(s) - 1] += 1
    t = tuple(cnt)
    # 最小のものだけ
    if t not in pattern:
        pattern[t] = x

#print(pattern)

T = int(input())
for i in range(T):
    N = input()
    cnt = [0] * 9
    for s in str(N):
        if s != '0':
            cnt[int(s) - 1] += 1
    t = tuple(cnt)

    if t in pattern:
        print(pattern[t])
    else:
        print('-1')