mod=10**9+7
n=int(input())
dp=[[0]*4 for _ in range(n+1)]
dp[0][0]=1
for i in range(1,n+1):
    for j in range(1,4):
        if i<j:
            continue
        for k in range(0,4):
            if j!=k:
                dp[i][j]+=dp[i-j][k]
        dp[i][j]%=mod
print(sum(dp[n])%mod)