#include<fstream.h>
int main()
{int i,nr,pos,n,p,nrc;
cin>>n>>p;
pos=0;
nr=0;
i=3;
while(pos==0)
  {if(i<n&&n%i!=0)
   nr++;
   if(i>n&&i%n!=0)
   nr++;
  if(nr==p)
   {cout<<i;
   pos=1;}
   i=i+2;}
   return 0;}