Buggy python submission (verdict: Time Limit Exceeded):
from itertools import combinations
import sys

read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

n = int(readline())
AB = list(list(map(int, readline().split())) for _ in range(n - 1))
m = int(readline())
UV = list(list(map(int, readline().split())) for _ in range(m))
graph = [[] for _ in range(n + 1)]
for a, b in AB:
    graph[a].append(b)
    graph[b].append(a)
# LCAが必要そう
# 慣れないけどdoublingしてみる？
# 実行時間に余裕があるし、毎回DFSしていい気がしてきた。
# 通った辺を(a,b)の形でsetに打ち込んで全部白になる場合の数を調べる方針


def dfs(s, g):
    kouho = set()
    par = [-1] * (n + 1)
    depth = [0] * (n + 1)
    stack = []
    stack.append(s)
    while stack:
        v = stack.pop()
        if v == g:
            break
        d = depth[v]
        for u in graph[v]:
            if u == par[v]:
                continue
            par[u] = v
            depth[u] = d + 1
            stack.append(u)
    # 経路復元
    p = g
    q = par[g]
    while q > 0:
        kouho.add((min(p, q), max(p, q)))
        p = q
        q = par[q]
    return kouho


sets = [[] for _ in range(m)]
for i, (u, v) in enumerate(UV):
    sets[i] = dfs(u, v)
ans = 0
for i in range(1, m + 1):
    kumiawase = list(combinations(range(m), i))
    for kumi in kumiawase:
        temp = set()
        for j in range(i):
            temp |= sets[kumi[j]]
        num = len(list(temp))
        ans += (-1) ** (i + 1) * (pow(2, n - 1) - pow(2, n - 1 - num))

print(ans)


Fixed submission:
from itertools import combinations
import sys

read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines


n = int(readline())
AB = list(list(map(int, readline().split())) for _ in range(n - 1))
m = int(readline())
UV = list(list(map(int, readline().split())) for _ in range(m))

graph = [[] for _ in range(n + 1)]
for i, (a, b) in enumerate(AB):
    graph[a].append((b, i))
    graph[b].append((a, i))


def dfs(s, g):
    kouho = 0
    par = [(0, 0)] * (n + 1)
    stack = []
    stack.append(s)
    while stack:
        v = stack.pop()
        if v == g:
            break
        for u, i in graph[v]:
            if u == par[v][0]:
                continue
            par[u] = (v, i)
            stack.append(u)
    # 経路復元
    p = g
    q, i = par[p]
    while q > 0:
        kouho |= 1 << i
        p = q
        q, i = par[q]
    return kouho


def popcnt(n):
    c = (n & 0x5555555555555555) + ((n >> 1) & 0x5555555555555555)
    c = (c & 0x3333333333333333) + ((c >> 2) & 0x3333333333333333)
    c = (c & 0x0F0F0F0F0F0F0F0F) + ((c >> 4) & 0x0F0F0F0F0F0F0F0F)
    c = (c & 0x00FF00FF00FF00FF) + ((c >> 8) & 0x00FF00FF00FF00FF)
    c = (c & 0x0000FFFF0000FFFF) + ((c >> 16) & 0x0000FFFF0000FFFF)
    c = (c & 0x00000000FFFFFFFF) + ((c >> 32) & 0x00000000FFFFFFFF)
    return c


sets = [0 for _ in range(m)]

for idx, (u, v) in enumerate(UV):
    sets[idx] = dfs(u, v)
ans = 0
for i in range(1, m + 1):
    kumiawase = list(combinations(range(m), i))
    for kumi in kumiawase:
        temp = 0
        for j in range(i):
            temp |= sets[kumi[j]]
        num = popcnt(temp)
        ans += (-1) ** (i + 1) * (pow(2, n - 1) - pow(2, n - 1 - num))

print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
from itertools import combinations
import sys

input = sys.stdin.buffer.readline

n = int(input())
graph = [[] for _ in range(n + 1)]
for _ in range(n - 1):
    a, b = map(int, input().split())
    graph[a].append(b)
    graph[b].append(a)
# LCAが必要そう
# 慣れないけどdoublingしてみる？
# 実行時間に余裕があるし、毎回DFSしていい気がしてきた。
# 通った辺を(a,b)の形でsetに打ち込んで全部白になる場合の数を調べる方針


def dfs(s, g):
    kouho = set()
    par = [-1] * (n + 1)
    depth = [0] * (n + 1)
    stack = []
    stack.append(s)
    while stack:
        v = stack.pop()
        if v == g:
            break
        d = depth[v]
        for u in graph[v]:
            if u == par[v]:
                continue
            par[u] = v
            depth[u] = d + 1
            stack.append(u)
    # 経路復元
    p = g
    q = par[g]
    while q > 0:
        kouho.add((min(p, q), max(p, q)))
        p = q
        q = par[q]
    return kouho


m = int(input())
sets = [[] for _ in range(m)]
for i in range(m):
    u, v = map(int, input().split())
    sets[i] = dfs(u, v)
ans = 0
for i in range(1, m + 1):
    kumiawase = list(combinations(range(m), i))
    for kumi in kumiawase:
        temp = set()
        for j in range(i):
            temp |= sets[kumi[j]]
        num = len(list(temp))
        ans += (-1) ** (i + 1) * (pow(2, n - 1) - pow(2, n - 1 - num))

print(ans)


Fixed submission:
from itertools import combinations
import sys

read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines


n = int(readline())
AB = list(list(map(int, readline().split())) for _ in range(n - 1))
m = int(readline())
UV = list(list(map(int, readline().split())) for _ in range(m))

graph = [[] for _ in range(n + 1)]
for i, (a, b) in enumerate(AB):
    graph[a].append((b, i))
    graph[b].append((a, i))


def dfs(s, g):
    kouho = 0
    par = [(0, 0)] * (n + 1)
    stack = []
    stack.append(s)
    while stack:
        v = stack.pop()
        if v == g:
            break
        for u, i in graph[v]:
            if u == par[v][0]:
                continue
            par[u] = (v, i)
            stack.append(u)
    # 経路復元
    p = g
    q, i = par[p]
    while q > 0:
        kouho |= 1 << i
        p = q
        q, i = par[q]
    return kouho


def popcnt(n):
    c = (n & 0x5555555555555555) + ((n >> 1) & 0x5555555555555555)
    c = (c & 0x3333333333333333) + ((c >> 2) & 0x3333333333333333)
    c = (c & 0x0F0F0F0F0F0F0F0F) + ((c >> 4) & 0x0F0F0F0F0F0F0F0F)
    c = (c & 0x00FF00FF00FF00FF) + ((c >> 8) & 0x00FF00FF00FF00FF)
    c = (c & 0x0000FFFF0000FFFF) + ((c >> 16) & 0x0000FFFF0000FFFF)
    c = (c & 0x00000000FFFFFFFF) + ((c >> 32) & 0x00000000FFFFFFFF)
    return c


sets = [0 for _ in range(m)]

for idx, (u, v) in enumerate(UV):
    sets[idx] = dfs(u, v)
ans = 0
for i in range(1, m + 1):
    kumiawase = list(combinations(range(m), i))
    for kumi in kumiawase:
        temp = 0
        for j in range(i):
            temp |= sets[kumi[j]]
        num = popcnt(temp)
        ans += (-1) ** (i + 1) * (pow(2, n - 1) - pow(2, n - 1 - num))

print(ans)