#include <iostream>
using namespace std;
 
int main() {
    int m, n;
    cin >> m >> n;
    int count = 0;
    for (int i = m; i <= n; i++) {
        if (i % 6 == 0 || i % 8 == 0) {
            count++;
        }
    }
    cout << count << endl;
    return 0;
}    
/**************************************************************
	Problem: 1982
	User: wengsihan
	Language: C++
	Result: Accepted
	Time:13 ms
	Memory:2072 kb
****************************************************************/