n = int(input())
m = 10**9+7
list1 = [1,0,0,0]
list2 = [0,0,0,0]


for x in range(n):
    for i in range(4):
        list2[i] = sum(list1) - list1[i]
    for i in range(4):
        list1[i] = list2[i] % m

print(list1[0]%m)