from functools import lru_cache n = int(input()) """@lru_cache(maxsize=1000000) def kp(n): if n< 3: return n else: return kp(n-1) + kp(n-2)//2""" def kp(n): if n in [1, 2]: return n else: a1, a2 = 1, 2 for _ in range(n-2): a1, a2 = a2, (a2+a1//2)%(10**9+7) return a2 print(kp(n)%(10**9+7))