Buggy python submission (verdict: Time Limit Exceeded):
from collections import deque
import heapq
N=int(input())
numbers=[[] for _ in range(N)]
for _ in range(N-1):
    a,b,c=map(int,input().split())
    a-=1
    b-=1
    numbers[a].append((b,c))
    numbers[b].append((a,c))
Q,K=map(int,input().split())
K-=1
keika=[]
for _ in range(Q):
    x,y=map(int,input().split())
    keika.append([x-1,y-1])
inf=pow(10,10)
visited=[inf for _ in range(N)]
visited[K]=0
stack=[K]
heapq.heapify(stack)
while len(stack)>0:
    n=heapq.heappop(stack)
    for s,t in numbers[n]:
        if visited[s]==inf:
            heapq.heappush(stack,s)
            visited[s]=min(visited[s],visited[n]+t)
for z in keika:
    print(visited[z[0]]+visited[z[1]])


Fixed submission:
from collections import deque
import heapq
N=int(input())
numbers=[[] for _ in range(N)]
for _ in range(N-1):
    a,b,c=map(int,input().split())
    a-=1
    b-=1
    numbers[a].append((b,c))
    numbers[b].append((a,c))
Q,K=map(int,input().split())
K-=1
keika=[]
for _ in range(Q):
    x,y=map(int,input().split())
    keika.append([x-1,y-1])
inf=pow(10,10)
visited=[inf for _ in range(N)]
visited[K]=0
stack=[K]
heapq.heapify(stack)
while len(stack)>0:
    n=heapq.heappop(stack)
    for s,t in numbers[n]:
        if visited[s]==inf:
            heapq.heappush(stack,s)
            visited[s]=visited[n]+t
for z in keika:
    print(visited[z[0]]+visited[z[1]])

Buggy python submission (verdict: Time Limit Exceeded):
from collections import deque
import heapq
N=int(input())
numbers=[[] for _ in range(N)]
for _ in range(N-1):
    a,b,c=map(int,input().split())
    a-=1
    b-=1
    numbers[a].append((b,c))
    numbers[b].append((a,c))
Q,K=map(int,input().split())
K-=1
keika=[]
for _ in range(Q):
    x,y=map(int,input().split())
    keika.append([x-1,y-1])
inf=pow(10,10)
visited=[inf for _ in range(N)]
visited[K]=0
stack=[K]
heapq.heapify(stack)
while len(stack)>0:
    n=heapq.heappop(stack)
    for s,t in numbers[n]:
        if visited[s]==inf:
            heapq.heappush(stack,s)
            visited[s]=min(visited[s],visited[n]+t)
for z in keika:
    print(visited[z[0]]+visited[z[1]])


Fixed submission:
from collections import deque
import heapq
N=int(input())
numbers=[[] for _ in range(N)]
for _ in range(N-1):
    a,b,c=map(int,input().split())
    a-=1
    b-=1
    numbers[a].append((b,c))
    numbers[b].append((a,c))
Q,K=map(int,input().split())
K-=1
keika=[]
for _ in range(Q):
    x,y=map(int,input().split())
    keika.append([x-1,y-1])
inf=pow(10,10)
visited=[inf for _ in range(N)]
visited[K]=0
stack=[K]
heapq.heapify(stack)
while len(stack)>0:
    n=heapq.heappop(stack)
    for s,t in numbers[n]:
        if visited[s]==inf:
            heapq.heappush(stack,s)
            visited[s]=visited[n]+t
for z in keika:
    print(visited[z[0]]+visited[z[1]])

Buggy python submission (verdict: Time Limit Exceeded):
from collections import deque
N=int(input())
numbers=[[] for _ in range(N)]
for _ in range(N-1):
    a,b,c=map(int,input().split())
    a-=1
    b-=1
    numbers[a].append((b,c))
    numbers[b].append((a,c))
Q,K=map(int,input().split())
K-=1
keika=[]
for _ in range(Q):
    x,y=map(int,input().split())
    keika.append([x-1,y-1])
inf=pow(10,10)
visited=[inf for _ in range(N)]
visited[K]=0
stack=deque([K])
while len(stack)>0:
    n=stack.pop()
    for s,t in numbers[n]:
        if visited[s]==inf:
            stack.appendleft(s)
            visited[s]=min(visited[s],visited[n]+t)
for z in keika:
    print(visited[z[0]]+visited[z[1]])


Fixed submission:
from collections import deque
import heapq
N=int(input())
numbers=[[] for _ in range(N)]
for _ in range(N-1):
    a,b,c=map(int,input().split())
    a-=1
    b-=1
    numbers[a].append((b,c))
    numbers[b].append((a,c))
Q,K=map(int,input().split())
K-=1
keika=[]
for _ in range(Q):
    x,y=map(int,input().split())
    keika.append([x-1,y-1])
inf=pow(10,10)
visited=[inf for _ in range(N)]
visited[K]=0
stack=[K]
heapq.heapify(stack)
while len(stack)>0:
    n=heapq.heappop(stack)
    for s,t in numbers[n]:
        if visited[s]==inf:
            heapq.heappush(stack,s)
            visited[s]=visited[n]+t
for z in keika:
    print(visited[z[0]]+visited[z[1]])

Buggy python submission (verdict: Time Limit Exceeded):
from collections import deque
N=int(input())
numbers=[[] for _ in range(N)]
for _ in range(N-1):
    a,b,c=map(int,input().split())
    a-=1
    b-=1
    numbers[a].append((b,c))
    numbers[b].append((a,c))
Q,K=map(int,input().split())
K-=1
keika=[]
for _ in range(Q):
    x,y=map(int,input().split())
    keika.append([x-1,y-1])
inf=pow(10,10)
visited=[inf for _ in range(N)]
visited[K]=0
stack=deque([K])
while len(stack)>0:
    n=stack.pop()
    for s,t in numbers[n]:
        if visited[s]==inf:
            stack.appendleft(s)
        visited[s]=min(visited[s],visited[n]+t)
for z in keika:
    print(visited[z[0]]+visited[z[1]])
    

Fixed submission:
from collections import deque
import heapq
N=int(input())
numbers=[[] for _ in range(N)]
for _ in range(N-1):
    a,b,c=map(int,input().split())
    a-=1
    b-=1
    numbers[a].append((b,c))
    numbers[b].append((a,c))
Q,K=map(int,input().split())
K-=1
keika=[]
for _ in range(Q):
    x,y=map(int,input().split())
    keika.append([x-1,y-1])
inf=pow(10,10)
visited=[inf for _ in range(N)]
visited[K]=0
stack=[K]
heapq.heapify(stack)
while len(stack)>0:
    n=heapq.heappop(stack)
    for s,t in numbers[n]:
        if visited[s]==inf:
            heapq.heappush(stack,s)
            visited[s]=visited[n]+t
for z in keika:
    print(visited[z[0]]+visited[z[1]])

Buggy python submission (verdict: Time Limit Exceeded):
from collections import deque
N=int(input())
numbers=[[] for _ in range(N)]
for _ in range(N-1):
    a,b,c=map(int,input().split())
    a-=1
    b-=1
    numbers[a].append((b,c))
    numbers[b].append((a,c))
Q,K=map(int,input().split())
K-=1
keika=[]
for _ in range(Q):
    x,y=map(int,input().split())
    keika.append([x-1,y-1])
inf=pow(10,10)
visited=[inf for _ in range(N)]
visited[K]=0
stack=deque([K])
while len(stack)>0:
    n=stack.pop()
    for s,t in numbers[n]:
        if visited[s]==inf:
            stack.appendleft(s)
        visited[s]=min(visited[s],visited[n]+t)
for z in keika:
    print(visited[z[0]]+visited[z[1]])
    

Fixed submission:
from collections import deque
import heapq
N=int(input())
numbers=[[] for _ in range(N)]
for _ in range(N-1):
    a,b,c=map(int,input().split())
    a-=1
    b-=1
    numbers[a].append((b,c))
    numbers[b].append((a,c))
Q,K=map(int,input().split())
K-=1
keika=[]
for _ in range(Q):
    x,y=map(int,input().split())
    keika.append([x-1,y-1])
inf=pow(10,10)
visited=[inf for _ in range(N)]
visited[K]=0
stack=[K]
heapq.heapify(stack)
while len(stack)>0:
    n=heapq.heappop(stack)
    for s,t in numbers[n]:
        if visited[s]==inf:
            heapq.heappush(stack,s)
            visited[s]=visited[n]+t
for z in keika:
    print(visited[z[0]]+visited[z[1]])