#include<bits/stdc++.h>
using namespace std;
int main(){
	int n,a,b,c=1,d=0;
	cin>>n>>b;
	c=n;
	while(b>=c){
		a=c;
		if(a%6==0 or a%8==0){
			d++;
		}
		c++;
	}
	cout<<d;
}
	    

	    
	
 

/**************************************************************
	Problem: 1982
	User: lvrenxiang
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/