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

int main(){
    int N;
    cin >> N;

    if(N == 1){
        cout << 1 << endl;
    }else{
        vector<bool> is_p(110010, true);
        vector<ll> p_list;
        is_p[0] = is_p[1] = false;
        for(ll i = 2; i <= 110010; ++i){
            if(!is_p[i]) continue;
            if(i > 100000) p_list.push_back(i);
            for(ll j = i+i; j <= 110010; j += i){
                is_p[j] = false;
            }
        }
        
        vector<ll> ans;
        int n = p_list.size();
        rep(i, 0, n) rep(j, i, n){
            ll val = ll(p_list[i]*p_list[j]);
            ans.push_back(val);
        }
        sort(ans.begin(), ans.end());

        cout << ans[N-2] << endl;
    }
    return 0;
}