def power(a, n):
    global x
    if n == 0:
        return 1
    elif n % 2 == 1:
        return (power(a % x, n - 1) * a) % x
    else:
        a2 = (power(a % x, n // 2)) % x
        return (a2 * a2) % x


x = int(input())
p = [x]
o = x
k = 0
i = 2
j = 0
while i * i < x+1:
    if x % i == 0:
        p.extend([i, x // i])
    i += 1

p.sort()
while j < len(p) and k == 0:
    if power(p[j], p[j]) == 0:
        o = p[j]
        k = 1
    j += 1

print(o)