from collections import defaultdict

t = int(input())
d = defaultdict(lambda: float('inf'))
for i in range(1, 100000):
    s = str(i*i)
    l = [0]*10
    for c in s:
        l[int(c)] += 1
    d[tuple(l)] = min(d[tuple(l)], i)
for _ in range(t):
    n = int(input())
    lis = [0]*10
    for c in str(n):
        lis[int(c)] += 1
    ans = float('inf')
    for i in range(lis[0]+1):
        lis2 = [i]+lis[1:]
        if tuple(lis2) in d:
            ans = min(ans, d[tuple(lis2)])
    if ans == float('inf'):
        print(-1)
    else:
        print(ans*ans)