N = int(input())

L = ((10 ** 9 + N - 1) // N) * N
while str(L)[-1] != "9": L += N

for i in range(10 ** 9 + 1):
    coef = 10 * i

    v = L + coef * N

    sv = str(v)[:-1]
    vs = sv[::-1]
    if sv == vs:
        print(v)
        break