MOD = 1000000007
N = int(input())

dp = [0] * (N + 1)
dp[0] = 1
for i in range(1, N + 1):
    for j in (2, 3):  # kp. kkp
        if i - j >= 0:
            dp[i] = (dp[i] + dp[i - j]) % MOD
    if i == N:
        for j in (1, 2):  # k, kk
            if i - j >= 0:
                dp[i] = (dp[i] + dp[i - j]) % MOD
print(dp[-1] % MOD)