"""

https://yukicoder.me/problems/no/1312

√までみればok?

それ以上は
p*x + x = N
(p+1) * x = N

を満たす最小のp

"""

import sys
from sys import stdin


N = int(input())

for p in range(2,10**6+1):

    n = N

    rem = n % p
    flag = True

    while n:
        if n % p != rem:
            flag = False
            break
        n //= p

    if flag:
        print (p)
        sys.exit()

for x in range(10**6,1,-1):
    if N % x == 0:
        pp = N // x
        print (pp-1)
        sys.exit()