n=int(input())
mod=(10**9)+7
dp1=[0,1,0]
for i in range(n-1):
    dp2=[0,0,0]
    if dp1[0]!=0:
        dp2[1]+=dp1[0]
    if dp1[1]!=0:
        dp2[0]+=dp1[1]
        dp2[2]+=dp1[1]
    if dp1[2]!=0:
        dp2[0]+=dp1[2]
    dp1=dp2    
print(sum(dp1)%mod)