N = int(input())
mod = 10**9 + 7
dp = [[None] * 3 for _ in range(N+1)]
dp[1][0] = 0
dp[1][1] = 1
dp[1][2] = 0

for i in range(1,N):
    dp[i+1][0] = (dp[i][1] + dp[i][2]) % mod
    dp[i+1][1] = dp[i][0]
    dp[i+1][2] = dp[i][1]

print(sum(dp[N]) % mod)