n,m = list(map(int,input().split()))
def sprt(xx):
    for i in range(int(xx)):
        if i * i == int(xx):
            return True
    return False
for i in range(n,m+1):
    s = str(i)
    for j in range(1,len(s)):
        str1 = s[:j]
        str2 = s[j:]
        if len(str1) > 0 and len(str2) > 0:
            if sprt(str1) and sprt(str2) and sprt(s):
                print(s)
                break

0分,无语······