"""
Problem:
A palindromic number reads the same both ways. The largest palindrome made from
the product of two 2-digit numbers is 9009 = 91 x 99.
Find the largest palindrome made from the product of two 3-digit numbers which
is less than N.
"""
def solution(n):
"""Returns the largest palindrome made from the product of two 3-digit
numbers which is less than n.
>>> solution(20000)
19591
>>> solution(30000)
29992
>>> solution(40000)
39893
"""
# fetches the next number
for number in range(n - 1, 10000, -1):
# converts number into string.
strNumber = str(number)
# checks whether 'strNumber' is a palindrome.
if strNumber == strNumber[::-1]:
divisor = 999
# if 'number' is a product of two 3-digit numbers
# then number is the answer otherwise fetch next number.
while divisor != 99:
if (number % divisor == 0) and (len(str(int(number / divisor))) == 3):
return number
divisor -= 1
if __name__ == "__main__":
print(solution(int(input().strip())))