#include<iostream.h>
#include<fstream.h>
void main()
{
 unsigned long v[1000],j,k,a,b,n,p,i,r;
 ifstream f("frac.in");
 ofstream g("frac.out");
 f>>n>>p;k=0;i=0;
 while(k<p)
  {i++;
   a=i;b=n;
   while(a!=b)
    if(a>b)
     a=a-b;
    else
     b=b-a;
   if(a==1)
    v[++k]=i;
  }
 cout<<v[k];
}