#pe004
def palindrome(check):
sc = str(check)
tr = ""
for i in sc[::-1]:
tr += i
if(sc==tr):
return True
else:
return False
ans = 0
for i in range(999,100,-1):
for j in range(999,100,-1):
ans_p = i*j
if palindrome(ans_p) and ans_p >= ans:
ans = ans_p
print(ans)