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


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