n = int(input())

l = []
for i in range(1, int(n**0.5)+1):
    if n % i == 0:
        l.append(i)
        l.append(n//i)
l = sorted(set(l))
l.remove(1)
if 2 in l:
    l.remove(2)


if l == []:
    print(n)
else:
    print(l[0])