#include<iostream>
#include <bits/stdc++.h>
//#include<vector>
using namespace std;
#define ll long long
bool prime[100000000];
int aux[100000000];

ll sieve(ll n){
    memset(prime, true, sizeof(prime));
    prime[0] = false;
    prime[1] = false;

    for(ll i = 2; i * i < 100000000; i++){
        if(prime[i]){
            for(ll j = i * i; j < 100000000; j +=i  ){
                prime[j] = 0;
            }
        }
    }

    ll k = 0;
    for (ll p=2; p<=  100000000; p++) {

          if (prime[p]){
           //   cout<<"**"<<endl;
            aux[k] = p;
           // cout<<aux[k]<<endl;
            k++;
        }
    }
    return aux[n - 1];
}

int main(){

    ll n;
    cin>>n;
    cout<<sieve(n)<<endl;

    return 0;
}