N = int(input())

s = 10 ** 9 // N
while True:
    if N * s >= 10 ** 9 and N * s % 10 == 9:
        break
    s += 1

def ok(x):
    if x % 10 != 9:
        return False
    xx = str(x)[:-1]
    return xx == xx[::-1]

for i in range(s, s + 10 ** 10, 10):
    if ok(N * i):
        print(N * i)
        exit()