Kabir likes Tara's smile and wants to look at her smile. They are sitting in the class and you are friends with Kabir. You have to place a mirror (point size)  in the front wall of the class so that Kabir can have a glimpse of Tara's smile.
Consider the front wall as x-axis . You are given the  coordinates of position of Kabir (x1,y1)$(x1,y1)$ and Tara  (x2,y2)$(x2,y2)$. Find the position where the mirror should be placed. 

-----Input:-----
- First line will contain T$T$, number of testcases. Then the testcases follow. 
- First line of each testcase contains two integers x1,y1$x1, y1$.
- Second line of each testcase contains two integers x2,y2$x2, y2$. 

-----Output:-----
For each testcase, print the x-coordinate of the mirror. Absolute error of 10−2$10^{−2}$ is allowed.

-----Constraints:-----
- 1≤T≤1000$1 \leq T \leq 1000$
- 1≤x1,y1,x2,y2≤105$1 \leq x1,y1,x2,y2 \leq 10^5 $

-----Sample Input:-----
1
1 1

4 4

-----Sample Output:-----
1.60

Source: codechef | Difficulty: UNKNOWN_DIFFICULTY


Solutions:
try:
	t = int(input())
	for _ in range(t):
		p = [int(x) for x in input().split()]
		q = [int(x) for x in input().split()]
		q[1] *= -1
		m = (q[1] - p[1]) / (q[0] - p[0])
		c = p[1] - m * p[0]
		print('{:.2f}'.format(-c / m))
except:
	pass


t = int(input())
l = []
for i in range(t):
	(x1, y1) = list(map(int, input().split()))
	(x2, y2) = list(map(int, input().split()))
	x = (x1 * y2 + x2 * y1) / (y1 + y2)
	l.append(x)
for i in l:
	print(i)


try:
	for _ in range(int(input())):
		(x1, y1) = list(map(float, input().split()))
		(x2, y2) = list(map(float, input().split()))
		result = (y1 * x2 + y2 * x1) / (y1 + y2)
		print(result)
except Exception:
	pass


t = int(input())
while t > 0:
	(x1, y1) = input().split()
	(x2, y2) = input().split()
	x1 = int(x1)
	x2 = int(x2)
	y1 = int(y1)
	y2 = int(y2)
	x = min(x1, x2)
	if x == x1:
		ans = y1 * (x2 - x1) / (y1 + y2)
		ans = x1 + ans
	else:
		ans = y2 * (x1 - x2) / (y1 + y2)
		ans = x2 + ans
	print('%.2f' % ans)
	t = t - 1


for _ in range(int(input())):
	(x1, y1) = list(map(int, input().split()))
	(x2, y2) = list(map(int, input().split()))
	m = (y2 - -y1) / (x2 - x1)
	y = y2
	x = x2
	c = y - m * x
	y = 0
	x = (y - c) / m
	print('{:.2f}'.format(x))


n = int(input())
for i in range(n):
	(x1, y1) = map(int, input().split())
	(x2, y2) = map(int, input().split())
	if x1 > x2:
		t = x1
		x1 = x2
		x2 = t
		t1 = y1
		y1 = y2
		y2 = t1
	r = y1 * (x2 - x1)
	r1 = r / (y2 + y1)
	print(x1 + r1)


t = int(input())
for _ in range(t):
	(x1, y1) = map(int, input().split())
	(x2, y2) = map(int, input().split())
	ans = (y1 * x2 + y2 * x1) / (y1 + y2)
	print('{0:.2f}'.format(ans))