#include <bits/stdc++.h>
#define rep(i, ss, ee) for (int i = ss; i < ee; ++i)
using namespace std;

void solve() {
  int a, b, ans = 0;
  cin >> a >> b;
  rep(i, 23, 26) if ((a < i and b < i) or (a > i and b > i)) ans++;
  cout << ans << endl;
}

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  solve();
}