local mfl, mce = math.floor, math.ceil
local mod = 1000000007

local function bmul(x, y)
  local x1, y1 = mfl(x / 31623), mfl(y / 31623)
  local x0, y0 = x - x1 * 31623, y - y1 * 31623
  return (x1 * y1 * 14122 + (x1 * y0 + x0 * y1) * 31623 + x0 * y0) % mod
end

local n = io.read("*n")
local a, b, c = {}, {}, {}
for i = 1, n - 1 do
  a[i], b[i], c[i] = io.read("*n", "*n", "*n")
end

local function uf_initialize(n)
  local parent = {}
  for i = 1, n do parent[i] = i end
  return parent
end

local function uf_findroot(idx, parent)
  local idx_update = idx
  while parent[idx] ~= idx do
    idx = parent[idx]
  end
  while parent[idx_update] ~= idx do
    parent[idx_update], idx_update = idx, parent[idx_update]
  end
  return idx
end

local ans = 0
local mul = 1
for irep = 1, 32 do
  local parent = uf_initialize(n)
  for i = 1, n - 1 do
    local ai, bi, ci = a[i], b[i], c[i]
    c[i] = mfl(c[i] / 2)
    if ci % 2 == 1 then
      local ra, rb = uf_findroot(ai, parent), uf_findroot(bi, parent)
      parent[rb], parent[bi] = ra, ra
    end
  end
  local g = {}
  for i = 1, n do
    local r = uf_findroot(i, parent)
    if g[r] then g[r] = g[r] + 1 else g[r] = 1 end
  end
  local ret = 0
  for _k, sz in pairs(g) do
    ret = ret + mfl(sz * (sz - 1) / 2)
  end
  ans = ans + bmul(ret, mul)
  mul = (mul * 2) % mod
end
print(ans % mod)