C = {i:set() for i in range(1,11)}
D = {}
for i in range(1,10**9+1):
    j = i*i
    if j>10**9:break
    j = tuple(sorted(list(str(j))))
    C[len(j)].add(j)
    if j not in D:
        D[j] = i*i
T = int(input())
for _ in range(T):
    N = str(int(input()))
    n = N.count("0")
    N = sorted(list(N))
    N = N[n:]
    ans = -1
    for i in range(n+1):
        if tuple(N) in C[len(N)]:
            ans = D[tuple(N)]
            break
        N = [0]+N
    print(ans)