Buggy python submission (verdict: Time Limit Exceeded):
N = int(input())
E = [[int(l) for l in input().split()] for _ in range(N-1)]
M = int(input())
L = [[int(l) for l in input().split()] for _ in range(M)]

class UnionFind():
    def __init__(self, n):
        self.n = n
        self.root = [-1]*(n+1)
        self.rnk = [0]*(n+1)
        
    def find_root(self, x):
        if self.root[x] < 0:
            return x
        else:
            self.root[x] = self.find_root(self.root[x])
            return self.root[x]
        
    def unite(self, x, y):
        x = self.find_root(x)
        y = self.find_root(y)
        if x == y:
            return
        elif self.rnk[x] > self.rnk[y]:
            self.root[x] += self.root[y]
            self.root[y] = x
        else:
            self.root[y] += self.root[x]
            self.root[x] = y
            if self.rnk[x] == self.rnk[y]:
                self.rnk[y] += 1
                
    def isSameGroup(self, x, y):
        return self.find_root(x) == self.find_root(y)

C = [set([]) for _ in range(M)]
for i in range(N-1):
    uf = UnionFind(N)
    for e in E:
        if e == E[i]:
            continue
        uf.unite(e[0], e[1])
    for l in range(M):
        if uf.isSameGroup(L[l][0], L[l][1]):
            continue
        C[l].add(i)

import itertools

ans = 0
L = [int(i) for i in range(M)]
for m in range(M+1):
    for P in itertools.combinations(L, m):
        white = set([])
        for j in P:
            white = white | C[j]
        if m%2:
            ans -= 1 << N-1-len(white)
        else:
            ans += 1 << N-1-len(white)
print(ans)

Fixed submission:
N = int(input())
E = [[int(l) for l in input().split()] for _ in range(N-1)]
M = int(input())
L = [[int(l) for l in input().split()] for _ in range(M)]

class UnionFind():
    def __init__(self, n):
        self.n = n
        self.root = [-1]*(n+1)
        self.rnk = [0]*(n+1)
        
    def find_root(self, x):
        if self.root[x] < 0:
            return x
        else:
            self.root[x] = self.find_root(self.root[x])
            return self.root[x]
        
    def unite(self, x, y):
        x = self.find_root(x)
        y = self.find_root(y)
        if x == y:
            return
        elif self.rnk[x] > self.rnk[y]:
            self.root[x] += self.root[y]
            self.root[y] = x
        else:
            self.root[y] += self.root[x]
            self.root[x] = y
            if self.rnk[x] == self.rnk[y]:
                self.rnk[y] += 1
                
    def isSameGroup(self, x, y):
        return self.find_root(x) == self.find_root(y)

C = [0]*M
for i in range(N-1):
    uf = UnionFind(N)
    for e in E:
        if e == E[i]:
            continue
        uf.unite(e[0], e[1])
    for l in range(M):
        if uf.isSameGroup(L[l][0], L[l][1]):
            continue
        C[l] |= 1 << i

import itertools

ans = 0
L = [int(i) for i in range(M)]
for m in range(M+1):
    for P in itertools.combinations(L, m):
        white = 0
        for j in P:
            white |= C[j]
        if m%2:
            ans -= 1 << N-1-bin(white).count("1")
        else:
            ans += 1 << N-1-bin(white).count("1")
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
N = int(input())
E = [[int(l) for l in input().split()] for _ in range(N-1)]
M = int(input())
L = [[int(l) for l in input().split()] for _ in range(M)]

class UnionFind():
    def __init__(self, n):
        self.n = n
        self.root = [-1]*(n+1)
        self.rnk = [0]*(n+1)
        
    def find_root(self, x):
        if self.root[x] < 0:
            return x
        else:
            self.root[x] = self.find_root(self.root[x])
            return self.root[x]
        
    def unite(self, x, y):
        x = self.find_root(x)
        y = self.find_root(y)
        if x == y:
            return
        elif self.rnk[x] > self.rnk[y]:
            self.root[x] += self.root[y]
            self.root[y] = x
        else:
            self.root[y] += self.root[x]
            self.root[x] = y
            if self.rnk[x] == self.rnk[y]:
                self.rnk[y] += 1
                
    def isSameGroup(self, x, y):
        return self.find_root(x) == self.find_root(y)

C = [set([]) for _ in range(M)]
for i in range(N-1):
    uf = UnionFind(N)
    for e in E:
        if e == E[i]:
            continue
        uf.unite(e[0], e[1])
    for l in range(M):
        if uf.isSameGroup(L[l][0], L[l][1]):
            continue
        C[l].add(i)

ans = 0
for i in range(2**M):
    cnt = 0
    white = set([])
    for j in range(M):
        if i & 1 << j:
            cnt += 1
            white = white | C[j]
    if cnt%2:
        ans -= pow(2, N-1-len(white))
    else:
        ans += pow(2, N-1-len(white))
print(ans)

Fixed submission:
N = int(input())
E = [[int(l) for l in input().split()] for _ in range(N-1)]
M = int(input())
L = [[int(l) for l in input().split()] for _ in range(M)]

class UnionFind():
    def __init__(self, n):
        self.n = n
        self.root = [-1]*(n+1)
        self.rnk = [0]*(n+1)
        
    def find_root(self, x):
        if self.root[x] < 0:
            return x
        else:
            self.root[x] = self.find_root(self.root[x])
            return self.root[x]
        
    def unite(self, x, y):
        x = self.find_root(x)
        y = self.find_root(y)
        if x == y:
            return
        elif self.rnk[x] > self.rnk[y]:
            self.root[x] += self.root[y]
            self.root[y] = x
        else:
            self.root[y] += self.root[x]
            self.root[x] = y
            if self.rnk[x] == self.rnk[y]:
                self.rnk[y] += 1
                
    def isSameGroup(self, x, y):
        return self.find_root(x) == self.find_root(y)

C = [0]*M
for i in range(N-1):
    uf = UnionFind(N)
    for e in E:
        if e == E[i]:
            continue
        uf.unite(e[0], e[1])
    for l in range(M):
        if uf.isSameGroup(L[l][0], L[l][1]):
            continue
        C[l] |= 1 << i

import itertools

ans = 0
L = [int(i) for i in range(M)]
for m in range(M+1):
    for P in itertools.combinations(L, m):
        white = 0
        for j in P:
            white |= C[j]
        if m%2:
            ans -= 1 << N-1-bin(white).count("1")
        else:
            ans += 1 << N-1-bin(white).count("1")
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
N = int(input())
E = [[int(l) for l in input().split()] for _ in range(N-1)]
M = int(input())
L = [[int(l) for l in input().split()] for _ in range(M)]

class UnionFind():
    def __init__(self, n):
        self.n = n
        self.root = [-1]*(n+1)
        self.rnk = [0]*(n+1)
        
    def find_root(self, x):
        if self.root[x] < 0:
            return x
        else:
            self.root[x] = self.find_root(self.root[x])
            return self.root[x]
        
    def unite(self, x, y):
        x = self.find_root(x)
        y = self.find_root(y)
        if x == y:
            return
        elif self.rnk[x] > self.rnk[y]:
            self.root[x] += self.root[y]
            self.root[y] = x
        else:
            self.root[y] += self.root[x]
            self.root[x] = y
            if self.rnk[x] == self.rnk[y]:
                self.rnk[y] += 1
                
    def isSameGroup(self, x, y):
        return self.find_root(x) == self.find_root(y)

C = [set([]) for _ in range(M)]
for i in range(N-1):
    uf = UnionFind(N)
    for e in E:
        if e == E[i]:
            continue
        uf.unite(e[0], e[1])
    for l in range(M):
        if uf.isSameGroup(L[l][0], L[l][1]):
            continue
        C[l].add(i)

ans = 0
for i in range(2**M):
    cnt = 0
    white = set([])
    for j in range(M):
        if i & 1 << j:
            cnt += 1
            white = white | C[j]
    if cnt%2:
        ans -= 2**(N-1-len(white))
    else:
        ans += 2**(N-1-len(white))
print(ans)

Fixed submission:
N = int(input())
E = [[int(l) for l in input().split()] for _ in range(N-1)]
M = int(input())
L = [[int(l) for l in input().split()] for _ in range(M)]

class UnionFind():
    def __init__(self, n):
        self.n = n
        self.root = [-1]*(n+1)
        self.rnk = [0]*(n+1)
        
    def find_root(self, x):
        if self.root[x] < 0:
            return x
        else:
            self.root[x] = self.find_root(self.root[x])
            return self.root[x]
        
    def unite(self, x, y):
        x = self.find_root(x)
        y = self.find_root(y)
        if x == y:
            return
        elif self.rnk[x] > self.rnk[y]:
            self.root[x] += self.root[y]
            self.root[y] = x
        else:
            self.root[y] += self.root[x]
            self.root[x] = y
            if self.rnk[x] == self.rnk[y]:
                self.rnk[y] += 1
                
    def isSameGroup(self, x, y):
        return self.find_root(x) == self.find_root(y)

C = [0]*M
for i in range(N-1):
    uf = UnionFind(N)
    for e in E:
        if e == E[i]:
            continue
        uf.unite(e[0], e[1])
    for l in range(M):
        if uf.isSameGroup(L[l][0], L[l][1]):
            continue
        C[l] |= 1 << i

import itertools

ans = 0
L = [int(i) for i in range(M)]
for m in range(M+1):
    for P in itertools.combinations(L, m):
        white = 0
        for j in P:
            white |= C[j]
        if m%2:
            ans -= 1 << N-1-bin(white).count("1")
        else:
            ans += 1 << N-1-bin(white).count("1")
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
N = int(input())
E = [[int(l) for l in input().split()] for _ in range(N-1)]
M = int(input())
L = [[int(l) for l in input().split()] for _ in range(M)]

class UnionFind():
    def __init__(self, n):
        self.n = n
        self.root = [-1]*(n+1)
        self.rnk = [0]*(n+1)
        
    def find_root(self, x):
        if self.root[x] < 0:
            return x
        else:
            self.root[x] = self.find_root(self.root[x])
            return self.root[x]
        
    def unite(self, x, y):
        x = self.find_root(x)
        y = self.find_root(y)
        if x == y:
            return
        elif self.rnk[x] > self.rnk[y]:
            self.root[x] += self.root[y]
            self.root[y] = x
        else:
            self.root[y] += self.root[x]
            self.root[x] = y
            if self.rnk[x] == self.rnk[y]:
                self.rnk[y] += 1
                
    def isSameGroup(self, x, y):
        return self.find_root(x) == self.find_root(y)

C = [set([]) for _ in range(M)]
for i in range(N-1):
    uf = UnionFind(N)
    for e in E:
        if e == E[i]:
            continue
        uf.unite(e[0], e[1])
    for l in range(M):
        if uf.isSameGroup(L[l][0], L[l][1]):
            continue
        C[l].add(i)

ans = 0
for i in range(2**M):
    cnt = 0
    white = set([])
    for j in range(M):
        if i & 1 << j:
            cnt += 1
            white = white | C[j]
    if cnt%2:
        ans -= 2**(N-1-len(white))
    else:
        ans += 2**(N-1-len(white))
print(ans)

Fixed submission:
N = int(input())
E = [[int(l) for l in input().split()] for _ in range(N-1)]
M = int(input())
L = [[int(l) for l in input().split()] for _ in range(M)]

class UnionFind():
    def __init__(self, n):
        self.n = n
        self.root = [-1]*(n+1)
        self.rnk = [0]*(n+1)
        
    def find_root(self, x):
        if self.root[x] < 0:
            return x
        else:
            self.root[x] = self.find_root(self.root[x])
            return self.root[x]
        
    def unite(self, x, y):
        x = self.find_root(x)
        y = self.find_root(y)
        if x == y:
            return
        elif self.rnk[x] > self.rnk[y]:
            self.root[x] += self.root[y]
            self.root[y] = x
        else:
            self.root[y] += self.root[x]
            self.root[x] = y
            if self.rnk[x] == self.rnk[y]:
                self.rnk[y] += 1
                
    def isSameGroup(self, x, y):
        return self.find_root(x) == self.find_root(y)

C = [0]*M
for i in range(N-1):
    uf = UnionFind(N)
    for e in E:
        if e == E[i]:
            continue
        uf.unite(e[0], e[1])
    for l in range(M):
        if uf.isSameGroup(L[l][0], L[l][1]):
            continue
        C[l] |= 1 << i

import itertools

ans = 0
L = [int(i) for i in range(M)]
for m in range(M+1):
    for P in itertools.combinations(L, m):
        white = 0
        for j in P:
            white |= C[j]
        if m%2:
            ans -= 1 << N-1-bin(white).count("1")
        else:
            ans += 1 << N-1-bin(white).count("1")
print(ans)