#include <iostream>
#include <vector>
using namespace std;

bool sieve[15500000];

int main()
{
    const long long sieve_size = 15500000;
    int k;
    cin >> k;
    for (int i = 2; i <= sieve_size; i++ )
    {
        if (!sieve[i])
        {
            if ( i*1ll*i <= sieve_size )
                for (int j = i*i; j <= sieve_size; j += i)
                    sieve[j] = true;
        }
    }

    vector<int>primes;
    for ( int i = 2; i <= sieve_size; i++ ) if ( sieve[i] == false ) primes.push_back(i);
    cout << primes[k-1] << '\n';
    return 0;
}