#include <bits/stdc++.h>
#define REP(i, n) for(int i = 0; (i) < (n); (i)++)
using namespace std;

int main()
{   
    int N; cin >> N;
    long p[12];
    int ind = 0;
    long prime = 100001;
    while(ind < 10){
        bool ok = true;
        for(long i=2; i*i<=prime; i++)
            if(prime % i == 0){
                ok = false;
                break;
            }
        if(ok){
            p[ind] = prime;
            ind++;
        }
        prime++;
    }
    //REP(i, 10) cout << p[i] << endl;
    vector<long> seki;
    REP(i, 10) for(int j=i; j<10; j++) seki.push_back(p[i]*p[j]);
    sort(seki.begin(), seki.end());
    if(N==1) cout << 1 << endl;
    else cout << seki[N-2] << endl;
    return 0;
}