#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cstdlib>
#include<vector>
#include<string>
#include<sstream>
#include<cmath>
#include<numeric>
#include<map>
#include<stack>
#include<queue>
using namespace std;


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






// EOF