n=int(input())
dp=[[i for i in[0]*3]for _ in range(n+1)]
dp[0][0]=1
for i in range(1,n+1):
    for j in range(2):
        dp[i][j+1]+=dp[i-1][j]
    for j in range(1,3):
        dp[i][0]+=dp[i-1][j]
print(sum(dp[n])%(10**9+7))