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