#include<iostream>
#include<vector>
#include<algorithm>
#include<utility>
#include<string>
#include<cmath>
#include<cstring>
#include<queue>
#include<map>
#include<climits>
#include<queue>

#define REP(i, n) for(int i = 0;i < n;i++)
#define REPR(i, n) for(int i = n;i >= 0;i--)
#define FOR(i, m, n) for(int i = m;i < n;i++)
#define FORR(i, m, n) for(int i = m;i >= n;i--)
#define SORT(v, n) sort(v, v+n);
#define VSORT(v) sort(v.begin(), v.end());
#define llong long long
#define pb(a) push_back(a)
using namespace std;
typedef pair<int, int> P;
typedef long long int ll;
typedef pair<ll,ll> LLP;
int dx[4] = {1,0,0,-1};
int dy[4] = {0,1,-1,0};
#define INF 1000000007
#define MOD 1000000007
#define ARRAY_MAX 105

int main(){

    int a,b;
    cin >> a >> b;
    int day = 3;
    for(int i = a;i <= b;i++){
        if(i == 23 || i == 24 || i == 25){
            day--;
        }
    }
    cout << day << endl;
    return 0;
}