ol_4_07

#include <iostream>
//#include <fstream>

using namespace std;

int main()
{

    //ifstream cin("input.txt");
    short n;
    cin>>n;

    short i = 1;
    long cur = 2;
    while(i!=n)
    {
        cur++;
        bool a = true;
        for (long j=2; j<cur; j++)
            if (cur%j==0)
            {
                a = false;
                break;
            }
        if (a)
            i++;
    }
    cout<<cur;

}