#include <bits/stdc++.h>
using namespace std;

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    int a, b;
    cin >> a >> b;

    vector<int> A = {23, 24, 25};

    vector<int> F(32, true);
    for(int i = a; i <= b; i++){
        F[i] = false;
    }

    int cnt = F[23] + F[24] + F[25];
    cout << cnt << endl;

    return 0;
}