You are given a tree consisting of n nodes numbered from 1 to n. The weights of edges of the tree can be any binary integer satisfying following Q conditions.

- 
		Each condition is of form u, v, x where u, v are nodes of the tree and x is a binary number. 

		For satisfying this condition,  sum of the weight of all the edges present in the path from node u to v of the tree, should have even if x = 0, odd otherwise. 
	

Now, you have to find out number of ways of assigning 0/1 (binary) weights to the edges of the tree satisfying the above conditions.
As the answer could be quite large, print your answer modulo 109 + 7.

-----Input-----
- The first line of input contains a single integer T denoting number of test cases.
- For each test case:
	
- First line contains two space separated integers n, Q.
- Each of the next n - 1 lines will contain two space separated integer  u, v denoting that there is an edge between vertex u and v in the tree.
- Each of the next Q lines will contain three space separated integer  u, v, x denoting a condition as stated in the probelm.

-----Output-----
- For each test case, output a single integer corresponding to the answer of the problem.

-----Constraints-----
- 1 ≤ u, v ≤ n
- 0 ≤ x ≤ 1

-----Subtasks-----
Subtask #1 : (10 points)
- Sum of each of variables n and Q over all the test cases ≤ 20

Subtask #2 : (20 points)
- Sum of each of variables n and Q over all the test cases ≤ 100

Subtask #3 : (30 points)
- Sum of each of variables n and Q over all the test cases ≤ 5000

Subtask #4 : (40 points)
- Sum of each of variables n and Q over all the test cases ≤ 100000

-----Example-----
Input:
3
3 2
1 2
1 3
1 2 0
1 3 0
3 0
1 2
2 3
3 1
1 2
2 3
1 2 1

Output:
1
4
2

-----Explanation-----
In the first example, 
You can only set the weight of each edge equal to 0 for satisfying the given condition. So, there is exactly one way of doing this. Hence answer is 1.

In the second example, 
There are two edges and there is no condition on the edges. So, you can assign them in 4 ways. 

In the third example, 
You have to assign the weight of edge between node 1 and 2 to 1. You can assign the remaining edge from 2 to 3 either 0 or 1. So, the answer is 2.

Source: codechef | Difficulty: UNKNOWN_DIFFICULTY


Solutions:
import sys

def powc(x, n, m):
	res = 1
	xx = x
	while n:
		if n & 1:
			res = res * xx % m
		xx = xx * xx % m
		n >>= 1
	return res

def circles(u):
	r = 0
	S = [(u, -1, 0)]
	Visited[u] = 0
	for s in S:
		for e in V[s[0]]:
			if e[0] != s[1]:
				if Visited[e[0]] == -1:
					Visited[e[0]] = s[2] ^ e[1]
					S.append((e[0], s[0], s[2] ^ e[1]))
				elif Visited[e[0]] != s[2] ^ e[1]:
					return -1
				else:
					r += s[0] < e[0]
	return r
T = int(sys.stdin.readline())
for _ in range(T):
	is_bad = False
	empty = 0
	(n, Q) = list(map(int, sys.stdin.readline().split()))
	for _ in range(n - 1):
		sys.stdin.readline()
	paths = []
	V = list(map(list, [[]] * n))
	for q in range(Q):
		(u, v, x) = list(map(int, sys.stdin.readline().split()))
		u -= 1
		v -= 1
		if (v, x ^ 1) in V[u]:
			is_bad = True
		elif (v, x) in V[u]:
			empty += 1
		elif u != v:
			V[u].append((v, x))
			V[v].append((u, x))
		elif x == 1:
			is_bad = True
		else:
			empty += 1
		paths.append((u, v, x))
	if is_bad:
		print(0)
	elif n <= 1:
		print(1)
	else:
		Visited = [-1] * n
		components = 0
		for i in range(n):
			if Visited[i] == -1:
				components += 1
				c = circles(i)
				if c == -1:
					is_bad = True
					break
				empty += c
		if is_bad:
			print(0)
		else:
			print(powc(2, n - 1 - (Q - empty), 10 ** 9 + 7))


import sys

def powc(x, n, m):
	res = 1
	xx = x
	while n:
		if n & 1:
			res = res * xx % m
		xx = xx * xx % m
		n >>= 1
	return res

def findRoot():
	S = [(0, -1)]
	for u in S:
		for w in V[u[0]]:
			if w[0] != u[1]:
				S.append((w[0], u[0]))
	S = [(S[-1][0], -1, 0)]
	D = [0] * n
	for u in S:
		for w in V[u[0]]:
			if w[0] != u[1]:
				D[w[0]] = u[2] + 1
				S.append((w[0], u[0], u[2] + 1))
	d = S[-1][2]
	size = d
	u = S[-1][0]
	while size / 2 < d:
		for w in V[u]:
			if D[w[0]] + 1 == D[u]:
				u = w[0]
				d -= 1
				break
	return u

class Node:

	def __init__(self, value, edge, parent=None):
		self.value = value
		self.edge = edge
		if parent:
			parent.addChild(self)
		else:
			self.parent = None
		self.children = []

	def addChild(self, node):
		node.parent = self
		self.children.append(node)

	def __repr__(self):
		r = repr(self.value)
		for v in self.children:
			r += ' ' + repr(v)
		return r

def hangTree(root):
	global NodesArray
	NodesArray = [None] * n
	S = [(root, Node(root, -1), -1)]
	NodesArray[root] = S[0][1]
	for u in S:
		for v in V[u[0]]:
			if v[0] != u[2]:
				node = Node(v[0], v[1], u[1])
				NodesArray[v[0]] = node
				S.append((v[0], node, u[0]))

def findPath2(u, v):
	n0 = NodesArray[u]
	n1 = NodesArray[v]
	q = [0] * n
	while n0.parent:
		q[n0.edge] ^= 1
		n0 = n0.parent
	while n1.parent:
		q[n1.edge] ^= 1
		n1 = n1.parent
	return q
T = int(sys.stdin.readline())
for _ in range(T):
	(n, Q) = list(map(int, sys.stdin.readline().split()))
	V = list(map(list, [[]] * n))
	W = [0] * n
	for i in range(n - 1):
		(u, v) = list(map(int, sys.stdin.readline().split()))
		u -= 1
		v -= 1
		V[u].append((v, i))
		V[v].append((u, i))
		W[u] += 1
		W[v] += 1
	easy = n == 1
	root = findRoot()
	hangTree(root)
	M = []
	for _ in range(Q):
		(u, v, x) = list(map(int, sys.stdin.readline().split()))
		if not easy:
			q = findPath2(u - 1, v - 1)
			q[-1] = x
			M.append(q)
	if easy:
		print(1)
		continue
	empty = [0] * n
	bad = [0] * n
	bad[-1] = 1
	is_there_bad = False
	empty_cnt = 0
	i = 0
	for q in M:
		i += 1
		if q == empty:
			empty_cnt += 1
			continue
		if q == bad:
			is_there_bad = True
			break
		o = q.index(1)
		for next in range(i, Q):
			if M[next][o] == 1:
				for k in range(n):
					M[next][k] ^= q[k]
	if is_there_bad:
		print(0)
	else:
		print(powc(2, n - 1 - Q + empty_cnt, 10 ** 9 + 7))


import sys

def powc(x, n, m):
	res = 1
	xx = x
	while n:
		if n & 1:
			res = res * xx % m
		xx = xx * xx % m
		n >>= 1
	return res

def findPath(u, v, x):
	S = [(u, v, x)]
	for s in S:
		if s[0] == v:
			return s[2]
		for e in V[s[0]]:
			if e[0] != s[1]:
				S.append((e[0], s[0], s[2] ^ e[1]))
	return None
T = int(sys.stdin.readline())
for _ in range(T):
	is_bad = False
	empty = 0
	(n, Q) = list(map(int, sys.stdin.readline().split(' ')))
	for _ in range(n - 1):
		sys.stdin.readline()
	paths = []
	V = list(map(list, [[]] * n))
	E = []
	for q in range(Q):
		(u, v, x) = list(map(int, sys.stdin.readline().split(' ')))
		u -= 1
		v -= 1
		if (v, x ^ 1) in V[u]:
			is_bad = True
		elif (v, x) in V[u]:
			empty += 1
		else:
			E.append((u, v, x))
			V[u].append((v, x))
			V[v].append((u, x))
		paths.append((u, v, x))
	if is_bad:
		print(0)
	else:
		while E:
			e = E.pop()
			x = findPath(e[0], e[1], e[2])
			V[e[0]].remove((e[1], e[2]))
			V[e[1]].remove((e[0], e[2]))
			if x == 1:
				is_bad = True
				break
			if x == 0:
				empty += 1
		if is_bad:
			print(0)
		else:
			print(powc(2, n - 1 - (Q - empty), 10 ** 9 + 7))


def modpow(a, x):
	if x == 0:
		return 1
	elif x % 2 == 0:
		t = modpow(a, x / 2)
		return t * t % 1000000007
	else:
		t = modpow(a, x / 2)
		return t * t * a % 1000000007
T = eval(input())
ans = [0] * T
for j in range(T):
	[N, Q] = [int(x) for x in input().split()]
	for i in range(N - 1):
		input()
	comp = list(range(N + 1))
	revcomp = []
	for i in range(N + 1):
		revcomp.append([i])
	sumcomp = [0] * (N + 1)
	flag = True
	rank = 0
	for i in range(Q):
		if not flag:
			input()
		else:
			[u, v, x] = [int(x) for x in input().split()]
			if comp[u] == comp[v]:
				if not (sumcomp[u] + sumcomp[v]) % 2 == x % 2:
					flag = False
			else:
				rank = rank + 1
				n1 = len(revcomp[comp[u]])
				n2 = len(revcomp[comp[v]])
				if n1 < n2:
					oldsu = sumcomp[u]
					l = revcomp[comp[v]]
					for w in revcomp[comp[u]]:
						l.append(w)
						comp[w] = comp[v]
						sumcomp[w] = (sumcomp[w] + sumcomp[v] + x + oldsu) % 2
				else:
					oldsv = sumcomp[v]
					l = revcomp[comp[u]]
					for w in revcomp[comp[v]]:
						l.append(w)
						comp[w] = comp[u]
						sumcomp[w] = (sumcomp[w] + sumcomp[u] + x + oldsv) % 2
	if not flag:
		ans[j] = 0
	else:
		ans[j] = modpow(2, N - rank - 1)
for j in range(T):
	print(ans[j])


T = eval(input())
ans = [0] * T
for j in range(T):
	[N, Q] = [int(x) for x in input().split()]
	for i in range(N - 1):
		input()
	comp = list(range(N + 1))
	revcomp = []
	for i in range(N + 1):
		revcomp.append([i])
	sumcomp = [0] * (N + 1)
	flag = True
	rank = 0
	for i in range(Q):
		if not flag:
			input()
		else:
			[u, v, x] = [int(x) for x in input().split()]
			if comp[u] == comp[v]:
				if not (sumcomp[u] + sumcomp[v]) % 2 == x % 2:
					flag = False
			else:
				rank = rank + 1
				n1 = len(revcomp[comp[u]])
				n2 = len(revcomp[comp[v]])
				if n1 < n2:
					oldsu = sumcomp[u]
					l = revcomp[comp[v]]
					for w in revcomp[u]:
						l.append(w)
						comp[w] = comp[v]
						sumcomp[w] = (sumcomp[w] + sumcomp[v] + x + oldsu) % 2
				else:
					oldsv = sumcomp[v]
					l = revcomp[comp[u]]
					for w in revcomp[v]:
						l.append(w)
						comp[w] = comp[u]
						sumcomp[w] = (sumcomp[w] + sumcomp[u] + x + oldsv) % 2
	if not flag:
		ans[j] = 0
	else:
		ans[j] = 2 ** (N - rank - 1)
for j in range(T):
	print(ans[j])