from math import sqrt, ceil

# is x anagram of y?
def anagram(x, y):
    x2 = [c for c in x]
    y2 = [c for c in y]
    x2.sort()
    y2.sort()
    return x2 == y2


# returns replacement list
def replacement(word, number):
    digits = [False] * 10
    for char in word[::-1]:
	digit = number % 10
	number /= 10

	if char in digits and digits[digit] != char:
	    return None

	if digits[digit] == False:
	    digits[digit] = char
	elif digits[digit] != char:
	    return None
    return digits


# find numbers matching the specified word in descending order
def match(word, numbers):
    result = []
    for n in numbers:
	digits = replacement(word, n)
	if digits != None:
	    result.append(n)
    
    result.sort(reverse=True)
    return result


f = open('098.txt', 'r')
words = f.read()
f.close()

maxlen = 14

words = set([ w.strip('"') for w in words.split(',') ])
squares = [ [ x*x for x in xrange(int(ceil(sqrt(10**n)))-1, int(ceil(sqrt(10**(n-1))))-1, -1) ] for n in xrange(1, maxlen+1) ]

maxsquare = 0

for l in xrange(1, maxlen+1):
    cur = [ w for w in words if len(w) == l ]

    for word1 in cur:
	for word2 in cur:
	    if word1 == word2 or word1 == word2[::-1] or not anagram(word1, word2):
		continue

	    m1 = match(word1, squares[l-1])
	    m2 = match(word2, squares[l-1])

	    # compare result lists
	    for n1 in m1:
		found = False
		for n2 in m2:
		    if replacement(word1, n1) == replacement(word2, n2):
			#print word1, word2, n1, n2
			if n1 > maxsquare:
			    maxsquare = n1
			found = True
			break
		if found:
		    break

print maxsquare