Buggy python submission (verdict: Time Limit Exceeded):
#F - Tree and constraints
import itertools
from collections import defaultdict
N = int(input())
G = [[] for i in range(N+1)]
edge = defaultdict(int)
for i in range(N-1):
    a, b = map(int, input().split())
    edge[(min(a, b), max(a, b))] = i+1
    G[a].append(b)
    G[b].append(a)
M = int(input())
que = [tuple(map(int, input().split())) for i in range(M)]
Data = [set([]) for i in range(M)]


def dfs(node):
    visited[node] = True
    for child in G[node]:
        if visited[child] == False:
            parent[child] = node
            dfs(child)


for i in range(M):
    s, g = que[i]
    visited = [False for i in range(N+1)]
    parent = [-1 for i in range(N+1)]
    dfs(s)
    now = g
    while parent[now] > 0:
        number = edge[(min(now, parent[now]), max(now, parent[now]))]
        Data[i].add(number)
        now = parent[now]
ans = 2**(N-1)

for i in range(1, M+1):
    # Mこからi+1こを選ぶ
    S = 0
    subset = set([])
    for v in itertools.combinations(Data, i):
        subset.clear()
        for x in v:
            subset = x | subset
        S += 2**(N-1-len(subset))
    ans -= (-1)**((i-1) % 2)*S
print(ans)

Fixed submission:
#F - Tree and constraints
import itertools
from collections import defaultdict
N = int(input())
G = [[] for i in range(N+1)]
edge = defaultdict(int)
for i in range(N-1):
    a, b = map(int, input().split())
    edge[(min(a, b), max(a, b))] = i+1
    G[a].append(b)
    G[b].append(a)
M = int(input())
que = [tuple(map(int, input().split())) for i in range(M)]
Data = [set([]) for i in range(M)]


def dfs(node):
    visited[node] = True
    for child in G[node]:
        if visited[child] == False:
            parent[child] = node
            dfs(child)


for i in range(M):
    s, g = que[i]
    visited = [False for i in range(N+1)]
    parent = [-1 for i in range(N+1)]
    dfs(s)
    now = g
    while parent[now] > 0:
        number = edge[(min(now, parent[now]), max(now, parent[now]))]
        Data[i].add(number)
        now = parent[now]
ans = 2**(N-1)
seq = [i for i in range(M)]
for i in range(1, M+1):
    # Mこからi+1こを選ぶ
    S = 0
    subset = set([])
    for v in itertools.combinations(seq, i):
        subset.clear()
        for x in v:
            subset = subset | Data[x]
        S += 2**(N-1-len(subset))
    ans -= (-1)**((i-1) % 2)*S
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
#F - Tree and constraints
import itertools
from collections import defaultdict
N = int(input())
G = [[] for i in range(N+1)]
edge = defaultdict(int)
for i in range(N-1):
    a, b = map(int, input().split())
    edge[(min(a, b), max(a, b))] = i+1
    G[a].append(b)
    G[b].append(a)
M = int(input())
que = [tuple(map(int, input().split())) for i in range(M)]
Data = [set([]) for i in range(M)]


def dfs(node):
    visited[node] = True
    for child in G[node]:
        if visited[child] == False:
            parent[child] = node
            dfs(child)


for i in range(M):
    s, g = que[i]
    visited = [False for i in range(N+1)]
    parent = [-1 for i in range(N+1)]
    dfs(s)
    now = g
    while parent[now] > 0:
        number = edge[(min(now, parent[now]), max(now, parent[now]))]
        Data[i].add(number)
        now = parent[now]
ans = 2**(N-1)

for i in range(1, M+1):
    # Mこからi+1こを選ぶ
    S = 0
    subset = set([])
    for v in itertools.combinations(Data, i):
        subset.clear()
        for x in v:
            subset = x | subset
        S += 2**(N-1-len(subset))
    ans -= (-1)**((i-1) % 2)*S
print(ans)

Fixed submission:
#F - Tree and constraints
import itertools
from collections import defaultdict
N = int(input())
G = [[] for i in range(N+1)]
edge = defaultdict(int)
for i in range(N-1):
    a, b = map(int, input().split())
    edge[(min(a, b), max(a, b))] = i+1
    G[a].append(b)
    G[b].append(a)
M = int(input())
que = [tuple(map(int, input().split())) for i in range(M)]
Data = [set([]) for i in range(M)]


def dfs(node):
    visited[node] = True
    for child in G[node]:
        if visited[child] == False:
            parent[child] = node
            dfs(child)


for i in range(M):
    s, g = que[i]
    visited = [False for i in range(N+1)]
    parent = [-1 for i in range(N+1)]
    dfs(s)
    now = g
    while parent[now] > 0:
        number = edge[(min(now, parent[now]), max(now, parent[now]))]
        Data[i].add(number)
        now = parent[now]
ans = 2**(N-1)
seq = [i for i in range(M)]
for i in range(1, M+1):
    # Mこからi+1こを選ぶ
    S = 0
    subset = set([])
    for v in itertools.combinations(seq, i):
        subset.clear()
        for x in v:
            subset = subset | Data[x]
        S += 2**(N-1-len(subset))
    ans -= (-1)**((i-1) % 2)*S
print(ans)