#include<fstream.h>
#include<iostream.h>
int prime(int a,int b)
{
	unsigned long r;
	if(a<b) {a+=b; b=a-b; a-=b;}
	r=a%b;
	while(r!=0)
	{
		a=b;
		b=r;
		r=a%b;
	}
	if(b==1) return 1;
	else return 0;
}
int main()
{
	unsigned long n,i=0,p;

ifstream fin("frac.in");
ofstream fout("frac.out");
fin>>n>>p;
while(p>0)
{
	i++;
	if(prime(n,i)==1) p--;
}
fout<<i;
fin.close();
fout.close();
return 0;
}