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

# dp[i][s] = i番目が、0:ケン1回目,1:ケン2回目,パ
dp = [[0] * 3 for i in range(N)]
dp[0][0] = 1

for i in range(1, N):
  dp[i][0] += dp[i - 1][2]
  dp[i][1] += dp[i - 1][0]
  dp[i][2] += dp[i - 1][0] + dp[i - 1][1]
  for j in range(3):
    dp[i][j] %= DIV
    
print(sum(dp[-1]) % DIV)