def f(k,d):
if k %2==1:
return 0
if k == 2:
d[2] = 3
return 3
try:
return d[k]%1000000007
except:
Mod = 1000000007
d[k] = f(k-2,d)*3
for i in range(0,k-2):
d[k] += f(i,d)*2
d[k] %= Mod
return d[k] % Mod
d = dict()
d[0] = 1
n = int(input())
print(f(n,d))