MOD = 10**9 + 7

n = int(input())

if n == 0:
    print(0)
else:
    dp0, dp1, dp2 = 0, 1, 0
    for _ in range(2, n + 1):
        new0 = (dp1 + dp2) % MOD
        new1 = dp0 % MOD
        new2 = dp1 % MOD
        dp0, dp1, dp2 = new0, new1, new2
    print((dp0 + dp1 + dp2) % MOD)