import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

import numpy as np

N = int(read())

x = np.arange(1,10**6 + 10)

div = x[N%x == 0]
div = np.union1d(div, N//div)
div = div[div >= 3]

answer = div[0]
print(answer)