#include <bits/stdc++.h>

// #include <atcoder/all>

using namespace std;
// using namespace atcoder;
 
#define DEBUG(x) cerr<<#x<<": "<<x<<endl;
#define DEBUG_VEC(v) cerr<<#v<<":";for(int i=0;i<v.size();i++) cerr<<" "<<v[i]; cerr<<endl;
#define DEBUG_MAT(v) cerr<<#v<<endl;for(int i=0;i<v.size();i++){for(int j=0;j<v[i].size();j++) {cerr<<v[i][j]<<" ";}cerr<<endl;}
typedef long long ll;
// #define int ll
 
#define vi vector<int>
#define vl vector<ll>
#define vii vector< vector<int> >
#define vll vector< vector<ll> >
#define vs vector<string>
#define pii pair<int,int>
#define pis pair<int,string>
#define psi pair<string,int>
#define pll pair<ll,ll>
template<class S, class T> pair<S, T> operator+(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first + t.first, s.second + t.second); }
template<class S, class T> pair<S, T> operator-(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first - t.first, s.second - t.second); }
template<class S, class T> ostream& operator<<(ostream& os, pair<S, T> p) { os << "(" << p.first << ", " << p.second << ")"; return os; }
#define X first
#define Y second
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define rep1(i,n) for(int i=1;i<=(int)(n);i++)
#define rrep(i,n) for(int i=(int)(n)-1;i>=0;i--)
#define rrep1(i,n) for(int i=(int)(n);i>0;i--)
#define REP(i,a,b) for(int i=a;i<b;i++)
#define in(x, a, b) (a <= x && x < b)
#define all(c) c.begin(),c.end()
template<class T> bool chmax(T &a, const T &b) { if (a<b) { a = b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a = b; return 1; } return 0; }
#define UNIQUE(v) v.erase(std::unique(v.begin(), v.end()), v.end());
const ll inf = 1000000001;
const ll INF = (ll)1e18 + 1;
const long double pi = 3.1415926535897932384626433832795028841971L;
#define Sp(p) cout<<setprecision(25)<< fixed<<p<<endl;
// int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
// int dx2[8] = { 1,1,0,-1,-1,-1,0,1 }, dy2[8] = { 0,1,1,1,0,-1,-1,-1 };
vi dx = {1, 0, -1, 0}, dy = {0, 1, 0, -1};
// vi dx2 = { 1,1,0,-1,-1,-1,0,1 }, dy2 = { 0,1,1,1,0,-1,-1,-1 };
#define fio() cin.tie(0); ios::sync_with_stdio(false);
// const ll MOD = 1000000007;
const ll MOD = 998244353;
// #define mp make_pair
//#define endl '\n'

double tan(int a, int b, int c) {
    return (a * 30 * 3600 + (b * 60 + c) * 30);
}
double chou(int a, int b, int c) {
    return 3600 * 6 * b + 6 * 60 * c;
}

signed main() {
    fio();
    
    int a, b;
    cin >> a >> b;
    a %= 12;
    if (tan(a, b, 0) == chou(a, b, 0)) {
        cout << 0 << endl;
        return 0;
    }
    int c = 0;
    int cnt = 0;
    bool flag = tan(a, b, 0) > chou(a, b, 0);
    while (true) {
        cnt++;
        c++;
        if (c == 60) {
            c = 0;
            b++;
        }
        if (b == 60) {
            b = 0;
            a++;
        }
        a %= 12;
        if (tan(a, b, c) == chou(a, b, c)) {
            cout << cnt << endl;
            return 0;
        }
        // if (abs(cnt - 1887) <= 1) {
        //     DEBUG(a);
        //     DEBUG(b);
        //     DEBUG(c);
        //     DEBUG(tan(a, b, c));
        //     DEBUG(chou(a, b, c));
        // }
        bool flag2 = tan(a, b, c) > chou(a, b, c);
        if (flag != flag2) {
            DEBUG(cnt);
            if (b != 0) {
                DEBUG(make_pair(pii(a, b), c));
                cout << cnt - 1 << endl;
                return 0;
            }
            else {
                flag = flag2;
            }
        }
    }
}