#include <fstream>
using namespace std;
ifstream f("frac.in");
ofstream g("frac.out");
long long n,i,p,k,gasit,x;
int cmmdc(int a,int b)
{
    int r;
    while(b)
    {
        r=a%b;
        a=b;
        b=r;

    }
    return a;
}
int main()
{
    f>>n>>p;
    for(i=1;i<=1000000&&gasit==0;i++)
    {if(cmmdc(n,i)==1)
    k++;
    if(k==p)
    {
        gasit=1;
        x=i;
    }
    }
    g<<x;
}