#include <bits/stdc++.h>

using namespace std;

#define FOR(i, a, b) for(int i = (a); i < (b); i++)
#define RFOR(i, a, b) for(int i = (a) - 1; i >= (b); i--)
#define SZ(a) int(a.size())
#define ALL(a) a.begin(), a.end()
#define PB push_back
#define MP make_pair
#define F first
#define S second

typedef long long LL;
typedef vector<int> VI;
typedef pair<int, int> PII;
typedef long double db;

const db EPS = 1e-9;

struct Pt
{
	db x, y;
	Pt operator+(const Pt& p) const
	{
		return {x + p.x, y + p.y};
	}
	Pt operator-(const Pt& p) const
	{
		return {x - p.x, y - p.y};
	}
	Pt operator*(db d) const
	{
		return {x * d, y * d};
	}
	Pt operator/(db d) const
	{
		return {x / d, y / d};
	}
};

db sq(const Pt& p)
{
	return p.x * p.x + p.y * p.y;
}

db abs(const Pt& p)
{
	return sqrt(sq(p));
}

int sgn(db x)
{
	return (EPS < x) - (x < -EPS);
}

Pt perp(const Pt& p)
{
	return {-p.y, p.x};
}

vector<Pt> circleCircle(const Pt& o1, db r1,
	const Pt& o2, db r2)
{
	Pt d = o2 - o1;
	db d2 = sq(d);
	if (sgn(d2) == 0)
	{
		assert(sgn(r2 - r1) != 0);
		return {};
	}
	db pd = (d2 + r1 * r1 - r2 * r2) / 2;
	db h2 = r1 * r1 - pd * pd / d2;
	if (sgn(h2) == -1)
		return {};
	Pt p = o1 + d * pd / d2;
	if (sgn(h2) == 0)
		return {p};
	Pt h = perp(d) * sqrt(h2 / d2);
	return {p - h, p + h};
}

int main()
{
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout << fixed << setprecision(15);
	int n;
	cin >> n;
	VI l(n), sufSum(n), sufMx(n), rMin(n);
	for (int& li : l)
		cin >> li;
	Pt target;
	cin >> target.x >> target.y;
	sufSum[n - 1] = l[n - 1];
	sufMx[n - 1] = l[n - 1];
	RFOR(i, n - 1, 0)
	{
		sufSum[i] = sufSum[i + 1] + l[i];
		sufMx[i] = max(sufMx[i + 1], l[i]);
	}
	FOR(i, 0, n)
	{
		rMin[i] = max(0, 2 * sufMx[i] - sufSum[i]);
	}
	db absTarget = abs(target);
	if (sgn(absTarget - rMin[0]) < 0)
	{
		if (sgn(absTarget) == 0)
			target = {(db)rMin[0], 0};
		else
			target = target * (rMin[0] / absTarget);
	}
	else if (sgn(absTarget - sufSum[0]) > 0)
		target = target * (sufSum[0] / absTarget);
	Pt p = {0, 0};
	vector<Pt> ans;
	FOR(i, 0, n - 1)
	{
		Pt q = {p.x + l[i], p.y};
		db dist = abs(target - q);
		// rMin[i + 1] <= dist && dist <= sufSum[i + 1]
		if (sgn(rMin[i + 1] - dist) <= 0 && sgn(dist - sufSum[i + 1]) <= 0)
		{
			p = q;
		}
		else
		{
			vector<Pt> vec;
			vec = circleCircle(p, l[i], target, sufSum[i + 1]);
			if (!vec.empty())
				p = vec[0];
			else
			{
				assert(rMin[i + 1] != 0);
				vec = circleCircle(p, l[i], target, rMin[i + 1]);
				assert(!vec.empty());
				p = vec[0];
			}
		}
		ans.PB(p);
	}
	ans.PB(target);
	for (const Pt& q : ans)
		cout << q.x << " " << q.y << "\n";
	assert(sgn(abs(ans[0]) - l[0]) == 0);
	FOR(i, 0, n - 1)
		assert(sgn(abs(ans[i + 1] - ans[i]) - l[i + 1]) == 0);
	return 0;
	
}