N = gets.to_i
M = 10**9 + 7

def mod_pow(x, n, m)
	res = 1
	while n > 0 do
		if n & 1 != 0 then
			res = res * x % m
		end
		x = x * x % m
		n >>= 1
	end
	res
end

a = mod_pow(3, N-1, M)
b = N % 2 == 0 ? 1 : -1
c = (a + b) * mod_pow(4, M-2, M) % M
d = (c * 3) % M

puts d