#!/usr/bin/python
from collections import defaultdict

def divisors(n):
    sq = int(n ** .5)
    res = [(i, n/i) for i in xrange(1, sq+1) if n%i==0]
    return res

n = int(raw_input())
arr = filter(lambda (x, y): x>2, divisors(n)) or [(n, 1)]
res = arr[0][0]
print res