import math

def nCr(n,r):
    f = math.factorial
    return f(n) / f(r) / f(n-r)

N = input()
MOD = 10**9 + 7

ans = 0
for i in xrange(N/2 + 1):
    #print i
    ans += nCr(i+(N-2*i)/3, i)
    ans %= MOD
print ans