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