import sys
from math import sqrt
input = sys.stdin.readline
N = int(input())
if N <= 2:
  print(N + 1)
  exit(0)

res = N + 1

def make_divisors(n):
    lower_divisors , upper_divisors = [], []
    i = 1
    while i*i <= n:
        if n % i == 0:
            lower_divisors.append(i)
            if i != n // i:
                upper_divisors.append(n//i)
        i += 1
    return lower_divisors + upper_divisors[::-1]

divs = make_divisors(N)[: - 1]
for i in divs:
  q = (N - i) // i
  if N % q == N // q: res = min(res, q)

for p in range(2, int(sqrt(N)) + 1):
  x = N
  r = x % p
  while x:
    if x % p != r: break
    x -= r
    x //= p
  else:
    res = min(res, p)
    break

print(res)