N = int(input())
MOD = 10**9 + 7

if N == 1:
    print(1)
    exit()
    
dp = [[0 for _ in range(3)] for _ in range(N+1)]
dp[2][0] = 1
dp[2][1] = 0
dp[2][2] = 1

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

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