#include<iostream.h>
#include<fstream.h>
 ifstream fi;
 ofstream fo;

main()
{
int z,q,a=1,nr=0;
long n,p;
fi.open("frac.in");
fo.open("frac.out");
fi>>n;
fi>>p;
q=n;
 do{n=q;
    z=a;
  while (a!=n){
	       if(a>n)a=a-n;
		  else n=n-a;
		   }
     if(n==1)nr++;
     a=z+1;
   }while(nr!=p);
 fo<<a-1;
fi.close();
fo.close();
}