#include <stdio.h>
#include <stdlib.h>
#include <math.h>
int main(){
  long  a,b,i,j,*r;
  long result = 0;
  scanf("%ld %ld",&a,&b);
  r=(long*)malloc(sizeof(long)*(b-a+1));
  for(i=a;i<=b;i++){
    r[i-a]=0;
    for(j=2;j<=sqrt(i);j++){
      if(i%j==0){
	r[i-a]=j;
	break;
      }
    }
  }
  j=0;
  for(i=a;i<=b;i++){
    if(r[i-a]>=j){
      j=r[i-a];
      result = i;
    }
  }
  printf("%ld\n",result);
  return 0;
}