from collections import defaultdict

D=defaultdict(lambda:[10**9]*10)
for i in range(1,10**5):
  if 10**9<i*i:
    break
  s=str(i*i)
  cnt=[0]*10
  for e in s:
    e=int(e)
    cnt[e]+=1
  t=tuple(cnt[1:])
  for id in range(cnt[0],10):
    D[t][id]=min(D[t][id],i*i)

test=int(input())
for _ in range(test):
  s=str(input())
  cnt=[0]*10
  for e in s:
    e=int(e)
    cnt[e]+=1
  t=tuple(cnt[1:])
  if D[t][cnt[0]]<10**9:
    print(D[t][cnt[0]])
  else:
    print(-1)