#include <vector>
using namespace std;
const size_t N = 10001;
int main()
{
vector<int> prime(N);
vector<int> square_of_prime(N);
prime[0] = 2;
square_of_prime[0] = 4;
size_t count(1);
int i(3);
for ( ; count != N; i += 2 )
{
int j(0);
bool is_prime(true);
for ( ; square_of_prime[j] <= i; ++j )
{
if ( i % prime[j] == 0 )
{
is_prime = false;
break;
}
}
if ( is_prime )
{
prime[count] = i ;
square_of_prime[count] = i * i;
++count;
}
}
cout << prime[N-1] << endl;
return 0;
}