nPrime1

import java.util.Scanner;
public class Input {
    public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
        int ref=0;
        int a = sc.nextInt();
        int i =0;
        int state=0;
        String prime="";
        if(a==1){
            System.out.println(2);
        }else if(a>1){
            ref=1;
        for(i =2;i<300000;i++){
            for(int j =2;j<i;j++){
                state = j;
                if(i%j==0){
                    break;
                }
            }
            if(state==i-1){
                ref+=1;
            }
            if(ref==a){
                System.out.println(i);
                break;
            }
        }
        }
        }
}