Given the value of n, print the n'th prime number.

Input : A single integer n. 
Output : A single number which is the n'th prime number.
Constraints : 
1 ≤ n ≤ 1000

SAMPLE INPUT
2

SAMPLE OUTPUT
3

Explanation

The first few prime numbers are:
2,3,5,7. So, the answer is 3.
import math
prime = []
n = 8000
b = int(math.sqrt(n))
flag = [True]*n
i=2
j=4
prime.append(i)
while j<n:
	flag[j]= False
	j+=i

i = 3
while i<=b:
	if flag[i] == True:
		j = i*i
		prime.append(i)
		while j<n:
			flag[j]= False
			j+=i
	i+=2


for i in range(b+1,n):
	if flag[i] == True:
		prime.append(i)

n = input();
print prime[n-1]