d = {}
for x in range(1, int(2e5)):
   Q = x*x
   digits = [int(c) for c in str(Q)]
   digits.sort()

   for c0 in range(10):
      if 10 < c0 + len(digits): break
      d.setdefault((0,) * c0 + tuple(digits), Q)


T = int(input())
ans = []
for _ in range(T):
   N = int(input())
   digits = [int(c) for c in str(N)]
   digits.sort()
   res = d.get(tuple(digits), -1)
   ans.append(res)

for a in ans:
   print(a)