#include<iostream>
#include<fstream>
using namespace std;
int main(void)
{
	int n,p[32000],z,e,a,i;
	ifstream in("ciur.in");
	ofstream out("ciur.out");
	/* Se citeste n afisati toate nr prime pana la n. */
	in>>n;
	z=1;
	p[1]=2;
	for(i=3;i<=n;i++)
	{
	
	//verif. daca i e prim, daca da il adaug in sirul p de dimens. z
		a=1;
		e=1;
		while(a<=z && e==1)
		{
			if(i%p[a]==0)
				e=0;
			a++;
		}
		if(e==1) {z++; p[z]=i;}
	}

	for(i=1;i<=z;i++)
	{
		out<<p[i];
	}
	in.close();
	out.close();
	return 0;
}