import sys
sys.setrecursionlimit(10000000)
MOD = 10 ** 9 + 7
INF = 10 ** 15

N = int(input())
dp = [[0]*3 for _ in range(N + 1)]
dp[1][0] = 1
if N >= 2:
    dp[2][1] = 1
if N >= 3:
    dp[3][2] = 1
for i in range(2,N + 1):
    dp[i][0] = (dp[i - 1][1] + dp[i - 1][2])%MOD
    if i - 3 >= 0:
        dp[i][1] = (dp[i - 2][0] + dp[i - 2][2])%MOD
    if i - 4 >= 0:
        dp[i][2] = (dp[i - 3][0] + dp[i - 3][1])%MOD
print(sum(dp[-1])%MOD)