#include <bits/stdc++.h>
using namespace std;

using ld = double;

const ld PI = atan2l(0, -1);

const int K = 100;

const int MAXN = 1e3;
vector<array<int, 3>> arr[MAXN];

const ld EPS = 1e-8;

void solve_() {
    int b, c, s;
    cin >> b >> c >> s;
    int n;
    cin >> n;
    for (int i = 0; i < n; ++i) {
        int m;
        cin >> m;
        arr[i].resize(m);
        for (int j = 0; j < m; ++j) {
            cin >> arr[i][j][0] >> arr[i][j][1] >> arr[i][j][2];
        }
    }

    ld l = 0, r = 1e4;
    vector<pair<ld, pair<ld, ld>>> opt;
    for (int _ = 0; _ < 40; ++_) {
        ld a = (l + r) / 2;
        bool found = false;
        bool found_pos = false;
        ld x = 0, y = 1;
        array<ld, 2> lft, rgh;
        for (int i = 0; i <= K; ++i) {
            /**if (y < 0) {
                found_pos = true;
                break;
            }*/
            //cerr << x << ',' << y << '\n';
            //ld x = cosl(PI / 2 / K * i), y = sinl(PI / 2 / K * i);
            pair<ld, pair<ld, ld>> sum(-1, make_pair(-1, -1));
            for (int shop = 0; shop < n; ++shop) {
                opt.clear();
                for (auto elem : arr[shop]) {
                    ld score = elem[1] * (elem[2] - a);
                    ld P = x * score + y * c;
                    ld Q = -y * s;
                    P *= elem[0];
                    Q *= elem[0];
                    opt.push_back(max(make_pair(P, make_pair(score * elem[0], c * elem[0])),
                      make_pair(Q, make_pair(ld(0), -s * elem[0]))));
                }
                sort(opt.begin(), opt.end());
                pair<ld, pair<ld, ld>> cur(0, make_pair(0, 0));
                for (int i = (int)opt.size() - 1; i >= 0; --i) {
                    if (i >= b || opt[i].first >= 0) {
                      cur.first += opt[i].first;
                      cur.second.first += opt[i].second.first;
                      cur.second.second += opt[i].second.second;
                    }
                }
                sum = max(sum, cur);
            }
            if (sum.first <= EPS) {
                found = true;
                break;
            }
            //cerr << sum.first << ' ' << sum.second.first << ',' << sum.second.second << '\n';
            if (sum.second.first >= 0 && sum.second.second >= 0) {
              found_pos = true;
              break;
            }
            if (sum.second.second >= 0) {
              x = sum.second.second;
              y = -sum.second.first;
            } else {
              found_pos = true;
              break;
              x = -sum.second.second;
              y = sum.second.first;
            }

        }
        if (found_pos) {
          l = a;
        } else if (found) {
            r = a;
        } else {
            l = a;
        }
    }
    ld res = (l + r) / 2;
    cout << res << "\n";
}

/// #define MULTITEST

main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    cout << fixed << setprecision(20);

    int tst = 1;
#ifdef MULTITEST
    cin >> tst;
#endif // MULTITEST
    while (tst--) {
        solve_();
    }
    return 0;
}