N=int(input())
dp = [[0]*3 for _ in range(N+1)]
dp[1][0]=1
if N>=2:
    dp[2][1]=1
if N>=3:
    dp[3][2]=1
mod=10**9+7

for i in range(0,N):
    for j in range(3):
        for jj in range(3):
            if j==jj:
                continue
            if i+jj+1>N:
                break
            dp[i+jj+1][jj]+=dp[i][j]
            dp[i+jj+1][jj]%=mod
print(sum(dp[-1])%mod)