#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (n); ++i)
using namespace std;
using ll = long long;

int main() {
    ll H, M;
    cin >> H >> M;
    H %= 12;
    cerr << "H = " << H << " M = " << M << endl;

    ll diff = 720 + H * 60 - M * 12 + M;
    diff %= 720;
    diff *= 60;
    cerr << "diff = " << diff << endl;
    ll div = 11;
    cout << (diff / (div)) << endl;
    return 0;
}