#include <bits/stdc++.h>

using namespace std;

int main() {
    int a, b;
    int d[] = { 23, 24, 25 };
    
    cin >> a >> b;
    
    int ct = 0; 
    for (int i : d) {
        if (i < a || i > b) {
            ct++;
        }
    }
    
    cout << ct << endl;
    
    return 0;
}