#include <stdio.h>

#define file_in "gfact.in"
#define file_out "gfact.out"

long long p,q;

inline long long solveq()
{
   long long i,nr;
   nr=2;
   i=2;
   while(nr%p!=0)
   {
	   i++;
	   nr*=i;
	   //i++;
   }
   
   return i;
}

int main()
{
int i;	
	freopen(file_in,"r",stdin);
	freopen(file_out,"w",stdout);
	
	scanf("%lld %lld", &p,&q);
	
	if (q==1)
	{
		printf("%lld", solveq()-1);
	}
	
	fclose(stdin);
	fclose(stdout);
	
	return 0;
}