Problem:
Score : 600 points

Problem Statement

There is a tree with N vertices numbered 1 to N.
The i-th edge in this tree connects Vertex a_i and Vertex b_i, and the color and length of that edge are c_i and d_i, respectively.
Here the color of each edge is represented by an integer between 1 and N-1 (inclusive). The same integer corresponds to the same color, and different integers correspond to different colors.

Answer the following Q queries:

Query j (1 \leq j \leq Q): assuming that the length of every edge whose color is x_j is changed to y_j, find the distance between Vertex u_j and Vertex v_j. (The changes of the lengths of edges do not affect the subsequent queries.)

Constraints

2 \leq N \leq 10^5

1 \leq Q \leq 10^5

1 \leq a_i, b_i \leq N

1 \leq c_i \leq N-1

1 \leq d_i \leq 10^4

1 \leq x_j \leq N-1

1 \leq y_j \leq 10^4

1 \leq u_j < v_j \leq N

The given graph is a tree.

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N Q
a_1 b_1 c_1 d_1
:
a_{N-1} b_{N-1} c_{N-1} d_{N-1}
x_1 y_1 u_1 v_1
:
x_Q y_Q u_Q v_Q

Output

Print Q lines. The j-th line (1 \leq j \leq Q) should contain the answer to Query j.

Sample Input 1

5 3
1 2 1 10
1 3 2 20
2 4 4 30
5 2 1 40
1 100 1 4
1 100 1 5
3 1000 3 4

Sample Output 1

130
200
60

The graph in this input is as follows:

Here the edges of Color 1 are shown as solid red lines, the edge of Color 2 is shown as a bold green line, and the edge of Color 4 is shown as a blue dashed line.

Query 1: Assuming that the length of every edge whose color is 1 is changed to 100, the distance between Vertex 1 and Vertex 4 is 100 + 30 = 130.

Query 2: Assuming that the length of every edge whose color is 1 is changed to 100, the distance between Vertex 1 and Vertex 5 is 100 + 100 = 200.

Query 3: Assuming that the length of every edge whose color is 3 is changed to 1000 (there is no such edge), the distance between Vertex 3 and Vertex 4 is 20 + 10 + 30 = 60. Note that the edges of Color 1 now have their original lengths.

Solution in Python (3.4.3) (judge verdict: Wrong Answer)

import sys
input = sys.stdin.readline
sys.setrecursionlimit(10**7)
import numpy as np

N,Q = map(int,input().split())
graph = [[] for _ in range(N+1)]
for _ in range(N-1):
    a,b,c,d = map(int,input().split())
    graph[a].append((b,c,d))
    graph[b].append((a,c,d))
query = [[int(x) for x in input().split()] for _ in range(Q)]

def euler_tour(x, tour_v, tour_d, depth = 0, parent=None):
    tour_v.append(x)
    tour_d.append(depth)
    for y, c, d in graph[x]:
        if y == parent:
            continue
        euler_tour(y, tour_v, tour_d, depth + 1, parent = x)
        tour_v.append(x)
        tour_d.append(depth)

tour_v = []
tour_d = []
euler_tour(1, tour_v, tour_d)
tour_d_arr = np.array(tour_d)
v_to_i = {v:i for i,v in enumerate(tour_v)}
v_to_d = dict(zip(tour_v, tour_d))

# sparse table
# 各インデックスから、2^i 項目分見て、一番depthの小さいインデックス
L = len(tour_v)
U = L.bit_length()
sp = [np.arange(L)]
for i in range(1,U):
    prev = sp[-1]
    width = 1 << (i-1)
    n1 = prev[:-width]
    n2 = prev[width:]
    sp.append(np.where(tour_d_arr[n1] < tour_d_arr[n2], n1, n2))

def LCA(x,y):
    return 1
    ix = v_to_i[x]
    iy = v_to_i[y]
    if ix > iy:
        ix,iy = iy,ix
    items = iy - ix + 1
    L = items.bit_length() - 1
    n1 = sp[L][ix]
    n2 = sp[L][iy - (1 << L) + 1]
    n = n1 if tour_d[n1] < tour_d[n2] else n2
    return tour_v[n]

tasks = [[] for _ in range(N+1)]
for i,(x,y,u,v) in enumerate(query):
    tasks[u].append((i,x,y,1))
    tasks[v].append((i,x,y,1))
    tasks[LCA(u,v)].append((i,x,y,-2))

answer = [0] * Q

def dfs(x = 1, sums = [0] * (N+1), nums = [0] * (N+1), total = 0, parent = 0):
    for i,c,d,coef in tasks[x]:
        answer[i] += coef * (total - sums[c] + nums[c] * d)
    for y,c,d in graph[x]:
        if y == parent:
            continue
        sums[c] += d
        nums[c] += 1
        total += d
        dfs(y, sums, nums, total, x)
        sums[c] -= d
        nums[c] -= 1
        total -= d
    return

dfs()
print('\n'.join(map(str,answer)))