# your code goes here
N=int(input())
M=10
for i in range(8):
    M*=10
M+=7
K1=[1]*N
K2=[0]*N
P=[0]*N
for i in range(1,N):
    K1[i]=P[i-1]
    K2[i]=K1[i-1]
    P[i]=K1[i-1]+K2[i-1]
    P[i]%=M
 #   print(P)
A=K1[N-1]+K2[N-1]+P[N-1]
A%=M
print(A)