T=int(input())
D=[[0 for _ in range(10)] for _ in range(31623)]
for i in range(1,31623):
    A=list(str(i**2))
    for a in A:
        D[i][int(a)]+=1
for _ in range(T):
    N=list(input())
    C=[0 for _ in range(10)]
    for n in N:
        C[int(n)]+=1
    ans=-1
    for i in range(1,31623):
        if C[1:]==D[i][1:] and C[0]>=D[i][0]:
            ans=i**2
            break
    print(ans)