n = int(input())
mod = 10**9 + 7

DP = [[0, 0, 0] for _ in range(n)]
DP[0][0] = 1
for i in range(n - 1):
    DP[i + 1][0] += DP[i][2]
    DP[i + 1][1] += DP[i][0]
    DP[i + 1][2] += DP[i][0] + DP[i][1]
    DP[i + 1][0] %= mod
    DP[i + 1][1] %= mod
    DP[i + 1][2] %= mod
print(sum(DP[-1]) % mod)