const input = require('fs').readFileSync('/dev/stdin', 'utf8');
const [A, B] = input
  .split(/\s/)
  .map(v => +v);
const MONTH = [...Array(31).keys()]
  .map(v => v + 1)
const contest = [23, 24, 25];
const trip = MONTH
  .slice(A - 1, B);

console.log(3 -
  contest
  .filter(v => trip.includes(v))
  .length);