#include<fstream>
#include<math.h>
#define DIM 20003
using namespace std;
ifstream in("prim.in");
ofstream out("prim.out");
int k,o,j,deviza,KOT,i,d,yo,ok,p[DIM*2],pr[DIM*100],np=1,nr;
long long v[100001];
void ciur()
{
    for( int i = 2; i < DIM*100; ++i ) {
        if( pr[i] ) continue;
        p[np++] = i;
        nr++;
        for( int j = i+i; j < DIM*100; j += i ) pr[j] = 1;
        if(nr>=k)
        break;
    }


}
int prim(int q)
{
    int d1;
    for(d1=2;d1*d1<=q;d1++)
    {
        if(q%d1==0)
        {
            return 1;
        }
    }
        return 0;
}
int main()
{
    in>>k;
    ciur();
    /*while(ok==1)
    {

        d=1;
        for(i=2;i<=yo/2;i++)
            if(yo%i==0)
        {
            i=yo/2;
            d=2;
        }
        if(d==1)
            {v[deviza]=yo;deviza++;k1--;}

        if(k1<=0)
            ok=0;
        yo++;
    }*/
    ok=0;
    KOT=9;
    while(ok==0)
    {
        deviza=0;
       for(j=1;j<=k;j++)
           if(KOT%p[j]==0)
        {
          deviza++;
           break;
        }
        if(deviza==0)
        {
            o=prim(KOT);
           if(o==1)
           {
                out<<KOT;
                ok=1;
           }
        }
        KOT+=2;
    }


    return 0;
}