#include<iostream>
using namespace std;
int a[40005]={2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97},k=24;
bool prime(int n){
    for(int i=1;i<=k;i++)
        if(n%a[i]==0) return false;
    return true;
 } 
int main(){
    int n;
    cin>>n;
    for(int i=101;k<=n;i+=2)
        if(prime(i)) a[++k]=i;
    cout<<a[n-1];
    return 0;
}