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