N=int(input())

if N<=2:
    print(1)
    exit()

dp=[[0 for i in range(3)] for j in range(N+1)]
dp[1][0]=1
dp[2][1]=1
dp[3][2]=1

MOD=int(1e9+7)

for i in range(N):
    for j in range(3):
        for k in range(3):
            if j==k:
                continue
            if i+k+1<=N:
                dp[i+k+1][k]+=dp[i][j]
                dp[i+k+1][k]%=MOD

print((dp[N][0]+dp[N][1]+dp[N][2])%MOD)