#include<fstream.h>

int main()
{	ifstream f("frac.in");
	ofstream g("frac.out");
	double p,n,i,a,b,aux;
	f>>n>>p;a=2;
	for(i=2;i<=p;)
	{       if(a!=n)
		{	b=n;aux=a;
			while(aux!=b)
				if(aux>b) aux-=b;
				else b-=aux;
			if(aux==1) {i++;a++;}
			else a++;
			if(i==p) {g<<a;break;}
		}
		else a++;
	}
	f.close();
	g.close();
	return 0;
}