#include <iostream>
#include <cstdio>
#include <vector>
#include <cmath>
#include <map>
#include <algorithm>
#include <string>
#include <utility>
#include <set>
#include <stack>
#include <deque>
#include <ctime>
#include <random>
#include <cassert>
#include <cmath>
#include <climits>
#include <queue>
#include <cstring>
#include <iomanip>
//#pragma GCC optimize ("O3")


#define int long long
#define fi(a,b) for (int i=a;i<b;i++)
#define fj(a,b) for (int j=a;j<b;j++)
#define fk(a,b) for (int k=a;k<b;k++)
#define fi1(a,b) for (int i=a-1;i>=b;i--)
#define fj1(a,b) for (int j=a-1;j>=b;j--)
#define fx(x,a) for (auto& x : a)

#define lb lower_bound
#define ub upper_bound

#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)


using namespace std;
typedef long long ll;
typedef char ch;
typedef string str;
typedef vector <long long> vl;
typedef vector <int> vi;
typedef vector<vector<long long>> vvl;
typedef vector<vector<int>> vvi;
typedef vector<pair<ll, ll>> vpll;
typedef vector<pair<int, int>> vpii;
typedef vector<vector<pair<ll, ll>>> vvpll;
typedef vector<vector<pair<int, int>>> vvpii;
typedef vector<char> vch;
typedef vector<vector<char>> vvch;
typedef vector<string> vs;
typedef map<ll, ll> mll;
typedef map<int, int> mii;
typedef map<ll, ch> mlch;
typedef map<int, ch> mich;
typedef map<ch, int> mchi;
typedef map<ch, ll> mchl;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef unsigned long long ull;


ll powmod(ll a, ll b, ll mod) {
	if (b == 0 || a == 1)
		return mod == 1 ? 0 : 1;

	if (b % 2 == 0) {
		ll k = powmod(a, b / 2, mod);
		return (k * k) % mod;
	}
	else {
		ll k = powmod(a, b / 2, mod);
		return ((k * k) % mod * a) % mod;
	}
}

ll gcd(ll a, ll b) {
	while (b) {
		a %= b;
		swap(a, b);
	}
	return a;
}

bool is_prime(ll n) {
	ll bound = sqrt(n);
	ll d = 2;
	while (d <= bound && n % d != 0)
		++d;
	return d * d > n;
}


const int MOD = 1000000007;
const int INF = 1000000050;
const int MX = 100010;
const double EPS = 1e-9;

mt19937 rnd;

struct inf {
	int l;
	int r;
	int f;
};

signed main() {
#ifdef LOCAL
	freopen("input.txt", "r", stdin);
	const int MAXN = 10000;
#endif
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);

	int n, v, F;
	cin >> n >> v >> F;
	cout.precision(10);
	ll sum = 0;
	ll allt = 0;
	fi(0, n) {
		int t, k;
		cin >> t >> k;
		fj(0, k) {
			int l;
			int r;
			int f;
			cin >> l >> r >> f;
			if (sum + (r - l) * f > F) {
				double left = l;
				double right = r;
				while (right - left > EPS) {
					double m = (right + left) / 2;
					if (sum + (m - l) * f >= F)
						right = m;
					else
						left = m;
				}
				cout <<double(allt) + left;
			} else if (sum + (r - l) * f == F) {
				cout << allt + r;
			}
			sum += (r - l) * f;
		}
		allt += t;
	}
	cout << -1;

	// you should actually read the stuff at the bottom
}

/* stuff you should look for
	* int overflow, array bounds
	* special cases (n=1?), set tle
	* do smth instead of nothing and stay organized
*/