#include <iostream>

using namespace std;

int a, b, ans = 0;

int main()
{
    cin >> a >> b;

    if (a <= 23 && 23 <= b)
        ans ++;

    if (a <= 37 && 37 <= b)
        ans ++;

    if (a <= 73 && 73 <= b)
        ans ++;

    if (a <= 53 && 53 <= b)
        ans ++;

    if (a <= 2 && 2 <= b)
        ans ++;

    if (a <= 3 && 3 <= b)
        ans ++;

    if (a <= 5 && 5 <= b)
        ans ++;

    if (a <= 7 && 7 <= b)
        ans ++;

    cout << ans;
    return 0;
}