#include<stdio.h>
long long cmmdc ( long long a, long long b)
{
	long long r;
	while(b)
		{
			r=a%b;
			a=b;
			b=r;
		}
	return a;
}


int main()
{
	freopen("frac.in","r",stdin);
	freopen("frac.out","w",stdout);
	
	long long num,n,p,i;
	
	scanf("%I64d%I64d",&n,&p);
	
	num=0;
	
	for(i=1;i<=n;i++) 
		{
			if(cmmdc(n,i)==1)
				{
					num++;
					if(num==p)
						{
							printf("%I64d",i);
							return 0;
						}
				}
		}
	return 0;
}