from heapq import heappush as push
from heapq import heappop as pop
from collections import deque


def get_ans(v):
    if v == -1:
        return
    get_ans(p[v])
    print(v)


def bfs(start):
    q = deque()
    q.append(start)
    r1 = [10**10] * n
    r1[start] = 0
    while len(q):
        v = q.popleft()
        for x in g[v]:
            if r1[x[0]] > r1[v] + x[1]:
                r1[x[0]] = r1[v] + x[1]
                q.append(x[0])
    return r1


n = int(input())
sp_s = list([] for i in range(n))
t = []
r = [10 ** 10] * n
r[0] = 0
sp = []
p = [-1] * n
h = []
for i in range(n):
    x, y = map(int, input().split())
    t.append(x)
    sp.append(y)
for i in range(n - 1):
    x, y, rr = map(lambda o: int(o) - 1, input().split())
    sp_s[x].append([y, rr + 1])
    sp_s[y].append([x, rr + 1])
push(h, (r[0], 0))
while h:
    curr, v = pop(h)
    if curr > r[v]:
        continue
    r1 = bfs(v)
    for v1 in range(n):
        if v == v1:
            continue
        if r[v1] * sp[v1] > r[v] * sp[v1] + t[v1] * sp[v1] * sp[v1] + r1[v1]:
            r[v1] = r[v] + t[v1] + r1[v1] / sp[v1]
            p[v1] = v
            push(h, (r[v1], v1))
ans = 0
for i in range(n):
    if r[i] > r[ans]:
        ans = i
print(r[ans])
get_ans()