n=int(input())
dp=[0]*(n+1)
dp[1]=1
dp[2]=2
dp[3]=2
dp[4]=3
if n<=4:
    print(dp[n])
    exit()

for i in range(5,n+1):
    dp[i]=(dp[i-2]+dp[i-3])%(10**9+7)
print(dp[n]%(10**9+7))