#include <bits/stdc++.h>
#define int long long 
using namespace std;

signed main() {
  int A, B;
cin >> A >> B;

int ans = 3;
for( int i=23; i <= 25; i++ ){
for( int j=A; j <= B; j++ ){
if( i == j ) ans--;
}
}

cout << ans << endl;
  
  
}