n = int(input())
m = 10**9+7
a = []
b = []
c = []
d = []
a.append(1)
b.append(0)
c.append(0)
d.append(0)

for x in range(n):
    a.append(b[x]+c[x]+d[x])
    b.append(a[x]+c[x]+d[x])
    c.append(a[x]+b[x]+d[x])
    d.append(a[x]+b[x]+c[x])

print(a[n]%m)