#include<bits/stdc++.h>
using namespace std;
int main() {
	int m,n;
	cin>>m>>n;
	int c = 0;
	for(int i = m;i <= n;i++){
		if(i % 6 == 0 || i % 8 == 0){
			c++;
		}
	}
	cout<<c;
	return 0;
}
/**************************************************************
	Problem: 1982
	User: admin
	Language: C++
	Result: Accepted
	Time:9 ms
	Memory:2072 kb
****************************************************************/