Problem: We have a tree with N vertices numbered 1 to N. The i-th edge in this tree connects Vertex a_i and Vertex b_i.
Consider painting each of these edges white or black. There are 2^{N-1} such ways to paint the edges. Among them, how many satisfy all of the following M restrictions?

* The i-th (1 \leq i \leq M) restriction is represented by two integers u_i and v_i, which mean that the path connecting Vertex u_i and Vertex v_i must contain at least one edge painted black.

Constraints

* 2 \leq N \leq 50
* 1 \leq a_i,b_i \leq N
* The graph given in input is a tree.
* 1 \leq M \leq \min(20,\frac{N(N-1)}{2})
* 1 \leq u_i < v_i \leq N
* If i \not= j, either u_i \not=u_j or v_i\not=v_j
* All values in input are integers.

Input

Input is given from Standard Input in the following format:


N
a_1 b_1
:
a_{N-1} b_{N-1}
M
u_1 v_1
:
u_M v_M


Output

Print the number of ways to paint the edges that satisfy all of the M conditions.

Examples

Input

3
1 2
2 3
1
1 3


Output

3


Input

2
1 2
1
1 2


Output

1


Input

5
1 2
3 2
3 4
5 3
3
1 3
2 4
2 5


Output

9


Input

8
1 2
2 3
4 3
2 5
6 3
6 7
8 6
5
2 7
3 5
1 6
2 8
7 8


Output

62

Solution (in PYTHON3):

Solution:
def examA():
    N = I()
    L = LI()
    L.sort()
    if sum(L)<=L[-1]*2:
        print("No")
    else:
        print("Yes")
    return

def examB():
    N, M = LI()
    A = [LI()for _ in range(N)]
    A.sort(key=lambda x:x[0])
    ans = 0
    for a,b in A:
        if M<=b:
            ans += a*M
            break
        ans += a*b
        M -= b
    print(ans)
    return

def examC():
    N = I()
    S = [SI()for _ in range(N)]
    D = defaultdict(int)
    for s in S:
        cur = []
        for i,j in Counter(s).items():
            cur.append((i,j))
        #print(cur)
        cur.sort()
        cur = tuple(cur)
        D[cur] += 1
    ans = 0
    for d in D.values():
        ans += (d-1)*d//2
    print(ans)
    return

def examD():
    N, K = LI()
    A = LI()
    S = [0]*(N+1)
    for i in range(N):
        S[i+1] = S[i]+A[i]
    ans = 0
    for i in range(N):
        l = i-1; r = N
        if S[-1]-S[i]<K:
            break
        while(r-l>1):
            now = (l+r)//2
            if S[now]-S[i]<K:
                l = now
            else:
                r = now
        #print(i,r)
        ans += (N-r+1)
    print(ans)
    return

def examE():
    # 区間加算、上書き、一点取得
    class SegmentTree:
        def __init__(self, n, ele, segfun):
            #####単位元######要設定0or1orinf
            self.ide_ele = ele
            self.segfun = segfun
            ####################
            self.n = n
            self.N0 = 1 << n.bit_length()
            self.data = [self.ide_ele] * (self.N0 * 2)

        def update_add(self, l, r, val):
            l += self.N0
            r += self.N0
            while l < r:
                if l & 1:
                    self.data[l] += val
                    l += 1
                if r & 1:
                    self.data[r - 1] += val
                    r -= 1
                l //= 2
                r //= 2

        def update(self, l, r, val):
            l += self.N0
            r += self.N0
            while l < r:
                if l & 1:
                    self.data[l] = self.segfun(self.data[l], val)
                    l += 1
                if r & 1:
                    self.data[r - 1] = self.segfun(self.data[r - 1], val)
                    r -= 1
                l //= 2
                r //= 2

        def query(self, i):
            i += len(self.data) // 2
            ret = self.data[i]
            while i > 0:
                i //= 2
                ret = self.segfun(ret, self.data[i])
            return ret

    N, D, A = LI()
    X = [LI()for _ in range(N)]
    X.sort()
    L = [0]*N
    for i in range(N):
        L[i] = X[i][0]
    S = SegmentTree(N,0,lambda a, b: a+b)
    ans = 0
    for i,[x,h] in enumerate(X):
        H = h - S.query(i)
        if H<=0:
            continue
        ne = bisect.bisect_right(L,x+2*D)
        #print(ne)
        need = (H-1)//A + 1
        S.update(i,ne,need*A)
        ans += need
    print(ans)
    return

def examF():
    N = I()
    V = [[]for _ in range(N)]
    Num_edge = {}
    for i in range(N-1):
        a, b = LI()
        a -= 1; b -= 1
        V[a].append(b)
        V[b].append(a)
        Num_edge[(a,b)] = i
        Num_edge[(b,a)] = i
    def dfs(S,s,p,g):
        now = s
        neS = []
        if now==g:
            return S
        for ne in V[now]:
            if ne==p:
                continue
            neS = dfs(S+(1<<Num_edge[(now,ne)]),ne,now,g)
            if neS:
                return neS
        return
    M = I()
    Q = [0]*M

    for i in range(M):
        a, b = LI()
        a -= 1; b -= 1
        Q[i] = dfs(0,a,-1,b)
    #print(Q)
    ans = pow(2,N-1)
    loop = 2**M
    for i in range(1,loop):
        cur = 0
        num = 0
        for k in range(M):
            if i&(1<<k)>0:
                num += 1
                cur |= Q[k]
        #print(i,cur)
        if num%2==1:
            ans -= 1 << (N - 1 - bin(cur).count("1"))
        else:
            ans += 1 << (N - 1 - bin(cur).count("1"))
    print(ans)
    return

import sys,bisect,itertools,heapq,math,random
from copy import deepcopy
from heapq import heappop,heappush,heapify
from collections import Counter,defaultdict,deque
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
def I(): return int(readline())
def LI(): return list(map(int,readline().split()))
def LSI(): return list(map(str,sys.stdin.readline().split()))
def LS(): return sys.stdin.readline().split()
def SI(): return sys.stdin.readline().strip()
global mod,mod2,inf,alphabet,_ep
mod = 10**9 + 7
mod2 = 998244353
inf = 10**18
_ep = 10**(-12)
alphabet = [chr(ord('a') + i) for i in range(26)]

sys.setrecursionlimit(10**7)

if __name__ == '__main__':
    examF()

"""
142
12 9 1445 0 1
asd dfg hj o o
aidn
"""