import math
N = int(input())

sieve_limit = int(math.sqrt(N))

prime_factor = []
prime = []

sieve = list(range(2,sieve_limit+1))
j = 0
remainder = N

while sieve:    
    factor = sieve[0]
    prime.append(factor)
    sieve = [i for i in sieve if i % factor != 0]
    while remainder % factor == 0:
    	remainder //= factor
    	prime_factor.append(factor)
    if remainder < factor:
    	break
prime_factor.append(remainder)

#print(prime)
#print(prime_factor)
K_limit = math.lcm(*[k-1 for k in prime_factor])
#print(K_limit)
remainder = K_limit