d = {}
for i in range(1, 10**5):
    if i * i > 10**9:
        break
    cnt = [0] * 10
    s = str(i * i)
    for c in s:
        cnt[int(c)] += 1
    if tuple(cnt) in d:
        continue
    d[tuple(cnt)] = i * i
for _ in range(int(input())):
    N = int(input())
    cnt = [0] * 10
    ans = float("inf")
    for c in str(N):
        cnt[int(c)] += 1
    t = cnt[0]
    for i in range(t + 1):
        cnt[0] = i
        if tuple(cnt) in d:
            ans = min(ans, d[tuple(cnt)])
    if ans == float("inf"):
        ans = -1
    print(ans)