def squareNoNo(n):
p = 0
for i in range(1, int(n ** 0.5) + 1):
p += mobius[i] * (n // (i * i))
return p
l, r = 0, 100000000000
mobius = [0] * 1000001
k = int(input())
mobius[1] = 1
for i in range(1, 1000001):
if mobius[i]:
for j in range(i * 2, 1000001, i):
mobius[j] -= mobius[i]
while l < r - 1:
mid = (l + r) // 2
if mid - squareNoNo(mid) < k:
l = mid
else:
r = mid
print(r)
