N = int(input())
KENDP = [0]*(N+1)
KENKENDP = [0]*(N+1)
PADP = [0]*(N+1)
PADP[0] = 1
MOD = 10**9+7
for i in range(1,N+1):
    KENDP[i] = PADP[i-1]%MOD 
    KENKENDP[i] = KENDP[i-1]%MOD 
    PADP[i] = (KENDP[i-1] + KENKENDP[i-1])%MOD

print((KENDP[N]+KENKENDP[N]+PADP[N])%MOD)