Buggy python submission (verdict: Runtime Error):
import sys
from collections import deque
sys.setrecursionlimit(10 ** 5)
input = sys.stdin.readline
N = int(input())
p = [deque([]) for _ in range(N)]

for i in range(N-1):
    a, b, c = [int(x) for x in input().strip().split()]
    p[a-1].append((b, c))
    p[b-1].append((a, c))

Q, K = [int(x) for x in input().strip().split()]

c = [-1] * N
f = [False] * N

def search(cp, cost):
    f[cp-1] = True
    for np, cos in p[cp-1]:
        if f[np-1]:
            continue
        c[np-1] = cost + cos
        f[np-1] = True
        search(np, cost + cos)

search(K, 0)
for q in range(Q):
    x, y = [int(x) for x in input().strip().split()]
    print(c[x-1]+c[y-1])

Fixed submission:
import sys
from collections import deque
sys.setrecursionlimit(10 ** 6)
input = sys.stdin.readline
n = int(input())
m = {}
np = [deque([]) for _ in range(n)]
for _ in range(n-1):
    a, b, c = [int(x) for x in input().strip().split()]
    m[(a, b)] = c
    m[(b, a)] = c
    np[a-1].append(b)
    np[b-1].append(a)

q, k = [int(x) for x in input().strip().split()]
master = [-1 for _ in range(n)]
master[k-1] = 0

def dfs(cur, pre, master):
    #print('cur = {}, pre = {}'.format(cur, pre))
    for p in np[cur-1]:
        if p == pre:
            continue
        master[p-1] = master[cur-1] + m[(cur, p)]
        dfs(p, cur, master)

dfs(k, -1, master)

for _ in range(q):
    x, y = [int(x) for x in input().strip().split()]
    print(master[x-1] + master[y-1])

Buggy python submission (verdict: Runtime Error):
import sys
from collections import deque
input = sys.stdin.readline
N = int(input())
p = [deque([]) for _ in range(N)]

for i in range(N-1):
    a, b, c = [int(x) for x in input().strip().split()]
    p[a-1].append((b, c))
    p[b-1].append((a, c))

Q, K = [int(x) for x in input().strip().split()]

c = [-1] * N
f = [False] * N

def search(cp, cost):
    f[cp-1] = True
    for np, cos in p[cp-1]:
        if f[np-1]:
            continue
        c[np-1] = cost + cos
        f[np-1] = True
        search(np, cost + cos)

search(K, 0)
for q in range(Q):
    x, y = [int(x) for x in input().strip().split()]
    print(c[x-1]+c[y-1])

Fixed submission:
import sys
from collections import deque
sys.setrecursionlimit(10 ** 6)
input = sys.stdin.readline
n = int(input())
m = {}
np = [deque([]) for _ in range(n)]
for _ in range(n-1):
    a, b, c = [int(x) for x in input().strip().split()]
    m[(a, b)] = c
    m[(b, a)] = c
    np[a-1].append(b)
    np[b-1].append(a)

q, k = [int(x) for x in input().strip().split()]
master = [-1 for _ in range(n)]
master[k-1] = 0

def dfs(cur, pre, master):
    #print('cur = {}, pre = {}'.format(cur, pre))
    for p in np[cur-1]:
        if p == pre:
            continue
        master[p-1] = master[cur-1] + m[(cur, p)]
        dfs(p, cur, master)

dfs(k, -1, master)

for _ in range(q):
    x, y = [int(x) for x in input().strip().split()]
    print(master[x-1] + master[y-1])

Buggy python submission (verdict: Runtime Error):
import sys
from collections import deque
sys.setrecursionlimit(10 ** 5)
input = sys.stdin.readline
n = int(input())
m = {}
np = [deque([]) for _ in range(n)]
for _ in range(n-1):
    a, b, c = [int(x) for x in input().strip().split()]
    m[(a, b)] = c
    m[(b, a)] = c
    np[a-1].append(b)
    np[b-1].append(a)

q, k = [int(x) for x in input().strip().split()]
master = [-1 for _ in range(n)]
master[k-1] = 0

def dfs(cur, pre, master):
    #print('cur = {}, pre = {}'.format(cur, pre))
    for p in np[cur-1]:
        if p == pre:
            continue
        master[p-1] = master[cur-1] + m[(cur, p)]
        dfs(p, cur, master)

dfs(k, -1, master)

for _ in range(q):
    x, y = [int(x) for x in input().strip().split()]
    print(master[x-1] + master[y-1])

Fixed submission:
import sys
from collections import deque
sys.setrecursionlimit(10 ** 6)
input = sys.stdin.readline
n = int(input())
m = {}
np = [deque([]) for _ in range(n)]
for _ in range(n-1):
    a, b, c = [int(x) for x in input().strip().split()]
    m[(a, b)] = c
    m[(b, a)] = c
    np[a-1].append(b)
    np[b-1].append(a)

q, k = [int(x) for x in input().strip().split()]
master = [-1 for _ in range(n)]
master[k-1] = 0

def dfs(cur, pre, master):
    #print('cur = {}, pre = {}'.format(cur, pre))
    for p in np[cur-1]:
        if p == pre:
            continue
        master[p-1] = master[cur-1] + m[(cur, p)]
        dfs(p, cur, master)

dfs(k, -1, master)

for _ in range(q):
    x, y = [int(x) for x in input().strip().split()]
    print(master[x-1] + master[y-1])

Buggy python submission (verdict: Runtime Error):
import sys
from collections import deque
input = sys.stdin.readline
n = int(input())
m = {}
np = [deque([]) for _ in range(n)]
for _ in range(n-1):
    a, b, c = [int(x) for x in input().strip().split()]
    m[(a, b)] = c
    m[(b, a)] = c
    np[a-1].append(b)
    np[b-1].append(a)

q, k = [int(x) for x in input().strip().split()]
master = [-1 for _ in range(n)]
master[k-1] = 0

def dfs(cur, pre, master):
    #print('cur = {}, pre = {}'.format(cur, pre))
    for p in np[cur-1]:
        if p == pre:
            continue
        master[p-1] = master[cur-1] + m[(cur, p)]
        dfs(p, cur, master)

dfs(k, -1, master)

for _ in range(q):
    x, y = [int(x) for x in input().strip().split()]
    print(master[x-1] + master[y-1])

Fixed submission:
import sys
from collections import deque
sys.setrecursionlimit(10 ** 6)
input = sys.stdin.readline
n = int(input())
m = {}
np = [deque([]) for _ in range(n)]
for _ in range(n-1):
    a, b, c = [int(x) for x in input().strip().split()]
    m[(a, b)] = c
    m[(b, a)] = c
    np[a-1].append(b)
    np[b-1].append(a)

q, k = [int(x) for x in input().strip().split()]
master = [-1 for _ in range(n)]
master[k-1] = 0

def dfs(cur, pre, master):
    #print('cur = {}, pre = {}'.format(cur, pre))
    for p in np[cur-1]:
        if p == pre:
            continue
        master[p-1] = master[cur-1] + m[(cur, p)]
        dfs(p, cur, master)

dfs(k, -1, master)

for _ in range(q):
    x, y = [int(x) for x in input().strip().split()]
    print(master[x-1] + master[y-1])

Buggy python submission (verdict: Time Limit Exceeded):
import sys
from collections import deque
input = sys.stdin.readline
n = int(input())
m = [[-1 for _ in range(n)] for _ in range(n)]
np = [deque([]) for _ in range(n)]
for _ in range(n-1):
    a, b, c = [int(x) for x in input().strip().split()]
    m[a-1][b-1] = c
    m[b-1][a-1] = c
    np[a-1].append(b)
    np[b-1].append(a)

q, k = [int(x) for x in input().strip().split()]
master = [-1 for _ in range(n)]
master[k-1] = 0

def dfs(cur, pre, master):
    #print('cur = {}, pre = {}'.format(cur, pre))
    for p in np[cur-1]:
        if p == pre:
            continue
        master[p-1] = master[cur-1] + m[cur-1][p-1]
        dfs(p, cur, master)

dfs(k, -1, master)

for _ in range(q):
    x, y = [int(x) for x in input().strip().split()]
    print(master[x-1] + master[y-1])

Fixed submission:
import sys
from collections import deque
sys.setrecursionlimit(10 ** 6)
input = sys.stdin.readline
n = int(input())
m = {}
np = [deque([]) for _ in range(n)]
for _ in range(n-1):
    a, b, c = [int(x) for x in input().strip().split()]
    m[(a, b)] = c
    m[(b, a)] = c
    np[a-1].append(b)
    np[b-1].append(a)

q, k = [int(x) for x in input().strip().split()]
master = [-1 for _ in range(n)]
master[k-1] = 0

def dfs(cur, pre, master):
    #print('cur = {}, pre = {}'.format(cur, pre))
    for p in np[cur-1]:
        if p == pre:
            continue
        master[p-1] = master[cur-1] + m[(cur, p)]
        dfs(p, cur, master)

dfs(k, -1, master)

for _ in range(q):
    x, y = [int(x) for x in input().strip().split()]
    print(master[x-1] + master[y-1])

Buggy python submission (verdict: Time Limit Exceeded):
import sys
input = sys.stdin.readline
n = int(input())
m = [[-1 for _ in range(n)] for _ in range(n)]
np = [[] for _ in range(n)]
for _ in range(n-1):
    a, b, c = [int(x) for x in input().strip().split()]
    m[a-1][b-1] = c
    m[b-1][a-1] = c
    np[a-1].append(b)
    np[b-1].append(a)

q, k = [int(x) for x in input().strip().split()]
master = [-1 for _ in range(n)]
master[k-1] = 0

def dfs(cur, pre, master):
    #print('cur = {}, pre = {}'.format(cur, pre))
    for p in np[cur-1]:
        if p == pre:
            continue
        master[p-1] = master[cur-1] + m[cur-1][p-1]
        dfs(p, cur, master)

dfs(k, -1, master)

for _ in range(q):
    x, y = [int(x) for x in input().strip().split()]
    print(master[x-1] + master[y-1])

Fixed submission:
import sys
from collections import deque
sys.setrecursionlimit(10 ** 6)
input = sys.stdin.readline
n = int(input())
m = {}
np = [deque([]) for _ in range(n)]
for _ in range(n-1):
    a, b, c = [int(x) for x in input().strip().split()]
    m[(a, b)] = c
    m[(b, a)] = c
    np[a-1].append(b)
    np[b-1].append(a)

q, k = [int(x) for x in input().strip().split()]
master = [-1 for _ in range(n)]
master[k-1] = 0

def dfs(cur, pre, master):
    #print('cur = {}, pre = {}'.format(cur, pre))
    for p in np[cur-1]:
        if p == pre:
            continue
        master[p-1] = master[cur-1] + m[(cur, p)]
        dfs(p, cur, master)

dfs(k, -1, master)

for _ in range(q):
    x, y = [int(x) for x in input().strip().split()]
    print(master[x-1] + master[y-1])