struct ModInt
	@@MOD = 1_000_000_007i64

	def self.mod
		@@MOD
	end

	def self.zero
		ModInt.new(0)
	end

	def initialize(n)
		@n = n.to_i64 % @@MOD
	end

	getter n : Int64

	def + : self
		self
	end

	def - : self
		ModInt.new(n != 0 ? @@MOD - @n : 0)
	end

	def +(m)
		ModInt.new(@n + m.to_i64 % @@MOD)
	end

	def -(m)
		ModInt.new(@n - m.to_i64 % @@MOD)
	end

	def *(m)
		ModInt.new(@n * m.to_i64 % @@MOD)
	end

	def /(m)
		raise DivisionByZeroError.new if m == 0
		a, b, u, v = m.to_i64, @@MOD, 1i64, 0i64
		while b != 0
			t = a // b
			a -= t * b
			a, b = b, a
			u -= t * v
			u, v = v, u
		end
		ModInt.new(@n * u)
	end

	def //(m)
		self / m
	end

	def **(m)
		t, res = self, ModInt.new(1)
		while m > 0
			res *= t if m.odd?
			t *= t
			m >>= 1
		end
		res
	end

	def ==(m)
		@n == m.to_i64
	end

	def !=(m)
		@n != m.to_i64
	end

	def succ
		self + 1
	end

	def pred
		self - 1
	end

	def to_i64 : Int64
		@n
	end

	delegate to_s, to: @n
	delegate inspect, to: @n
end

n = read_line.to_i
g = Array.new(n) { [] of Int32 }
flag = [false] * n
n.pred.times do
  a, b = read_line.split.map &.to_i.pred
  g[a] << b
  flag[b] = true
end

def dfs(v, dist, g)
  res = ModInt.new((1i64..dist.to_i64).sum)
  g[v].each do |u|
    res += dfs(u, dist + 1, g)
  end
  res
end

puts dfs(flag.index(false).not_nil!, 0, g)