#include <iostream>
#include <sstream>
#include <fstream>
#include <string>
#include <vector>
#include <deque>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <algorithm>
#include <functional>
#include <utility>
#include <bitset>
#include <cmath>
#include <cstdlib>
#include <ctime>
#include <cstdio>

using namespace std;

#define REP(i, n) for (int i = 0; i < n; i++) 

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	int a, b;
	cin >> a >> b;
	int ans = 3;
	for (int i = a; i <= b; i++) {
		if (i == 23 || i == 24 || i == 25) ans--;
	}
	cout << ans << endl;
}