#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i = 0; i < (n);i++)
#define sz(x) int(x.size())
typedef long long ll;
typedef long double ld;
typedef pair<int,int> P;
constexpr int mod = 1e9+7;

int main() {
  int a, b;
  cin >> a >> b;
  a = a * 3600 + b * 60;
  int c = a % 3600*12;
  int d = a % (12 * 3600);
  if (c == d) {
    cout << 0 << endl;
    return 0;
  }
  d -= c;
  if (d < 0) d += 12 * 3600;
  cout << d / 11 << endl;
  return 0; 
}