n = int(input())

t = 1

while True:
    l = list(str((t*10+1)*n))

    l = l[:-1]

    mode = True
    for i in range(len(l)//2):
        if l[i] != l[-i-1]:
            mode = False
    
    if mode:
        print((t*10+1)*n)
        quit()
    
    t += 1