#include <iostream>
#include <algorithm>
#include <cstdio>
#include <string>

#define ll long long
#define NULL -1

using namespace std;

int main(){

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

   int ans=3;
   for(int i=a;i<=b;++i) if(i>=23&&i<=25) ans--;
   cout<<ans<<endl;

   return 0;
}