local mod = 1000000007
local mfl = math.floor
local function badd(x, y)
  return (x + y) % mod
end

local n = io.read("*n")
local edge = {}
local parent = {}
local root = {}
for i = 1, n do
  edge[i] = {}
  parent[i] = 0
  root[i] = true
end
for i = 1, n - 1 do
  local a, b = io.read("*n", "*n")
  table.insert(edge[a], b)
  root[b] = false
end
for i = 1, n do
  if root[i] then root = i break end
end
local len = {}
for i = 1, n do
  len[i] = -1
end
len[root] = 0
local tasks = {root}
for i = 1, n do
  local src = tasks[i]
  for j = 1, #edge[src] do
    local dst = edge[src][j]
    len[dst] = len[src] + 1
    table.insert(tasks, dst)
  end
end
local ret = 0
for i = 1, n do
  ret = badd(ret, mfl(len[i] * (len[i] + 1) / 2))
end
print(ret)