#include <bits/stdc++.h>
#define rep(i, a, n) for(int i = a; i < n; i++)
using namespace std;
using ll = long long;
using P = pair<int, int>;

bool is_prime(ll x){
    for(int i = 2; i*i <= x; i++){
        if(x%i == 0) return false;
    }
    return true;
}

int main()
{
    int n;
    cin >> n;
    int cnt = 0;
    vector<ll> a;
    a.push_back(1);
    ll m = 100001;
    while(cnt < n){
        rep(i, 2, 100001){
            if(m%i == 0){
                m++;
            }
        }
        if(is_prime(m)){
            m++;
        }
        else{
            a.push_back(m);
            cnt++;
        }
    }
    cout << a[n-1] << endl;
    return 0;
}