#include <bits/stdc++.h>
using ll = long long;
// #define int ll
#define FOR(i, a, b) for (int i = (a); i < int(b); ++i)
#define RFOR(i, a, b) for (int i = (b)-1; i >= int(a); --i)
#define rep(i, n) FOR(i, 0, n)
#define rep1(i, n) FOR(i, 1, int(n) + 1)
#define rrep(i, n) RFOR(i, 0, n)
#define rrep1(i, n) RFOR(i, 1, int(n) + 1)
#define all(c) begin(c), end(c)
// const int MOD = 1000000007;

template <typename T>
void __print__(std::ostream &os, const char *, const char *tail, const T &fst) {
    os << fst << tail;
}
template <typename Fst, typename... Rst>
void __print__(std::ostream &os, const char *del, const char *tail, const Fst &fst,
               const Rst &... rst) {
    os << fst << del;
    __print__(os, del, tail, rst...);
}

#ifdef LOCAL
#define dump(...)                                         \
    do {                                                  \
        std::ostringstream os;                            \
        os << __LINE__ << ":\t" << #__VA_ARGS__ << " = "; \
        __print__(os, ", ", "\n", __VA_ARGS__);           \
        std::cerr << os.str();                            \
    } while (0)
#else
#define dump(...)
#endif

template <typename Fst, typename... Rst>
void println(const Fst &fst, const Rst &... rst) {
    __print__(std::cout, "\n", "\n", fst, rst...);
}
template <typename Fst, typename... Rst>
void print(const Fst &fst, const Rst &... rst) {
    __print__(std::cout, " ", "\n", fst, rst...);
}

template <typename iter>
void println_(iter bgn, iter end) {
    while (bgn != end) println(*bgn++);
}

template <typename iter>
void print_(iter bgn, iter end) {
    while (bgn != end) {
        std::cout << *bgn++;
        std::cout << (bgn == end ? "\n" : " ");
    }
}

int _ = (std::cout.precision(10), std::cout.setf(std::ios::fixed), std::cin.tie(0),
         std::ios::sync_with_stdio(0), 0);

template <typename T>
std::vector<T> ndarray(int n, T v) {
    return std::vector<T>(n, v);
}
template <typename... Args>
auto ndarray(int n, Args... args) {
    auto val = ndarray(args...);
    return std::vector<decltype(val)>(n, move(val));
}

template <typename T>
bool umax(T &a, const T &b) {
    return a < b ? a = b, true : false;
}

template <typename T>
bool umin(T &a, const T &b) {
    return a > b ? a = b, true : false;
}

using namespace std;

int main() {
    int n;
    while (cin >> n) {
        vector<int> start(n), end(n), power(n);
        rep(i, n) {
            int m, d, v, s;
            cin >> m >> d >> v >> s;
            --m;
            --d;
            start[i] = m*30 + d;
            end[i] = start[i] + v - 1;
            power[i] = s;
        }

        const int Y = 30*12;
        int ans = 1e9;
        rep(d, Y) {
            int maxi = 0;
            rep(i, n) {
                int cand;
                int s = start[i], e = end[i];
                int s2 = s + Y, e2 = e - Y;
                if ((s <= d && d <= e) || (s <= d + Y && d + Y <= e)) {
                    // cout << "i";
                    cand = power[i];
                } else if (e < d && d < s2) {
                    // cout << "a";
                    cand = max(0, power[i] - min(d - e, s2 - d));
                } else {
                    // cout << "b";
                    cand = max(0, power[i] - min(d - e2, s - d));
                }
                maxi = max(maxi, cand);
            }
            // cout << maxi << ' ';
            ans = min(ans, maxi);
        }
        // cout << endl;
        cout << ans << endl;
    }
}

Measured memory_bytes: 3196