import sys
sys.setrecursionlimit(1000000000)
N = int(input())


memo1 = [ -1 for i in range(N+1)]
memo2 = [ -1 for i in range(N+1)]
memo3 = [ -1 for i in range(N+1)]

MOD = 10**9 + 7

def r1(n):
    if n == 1:
        return 1
    elif n == 2:
        return 0
    elif n == 3:
        return 1
    else:
        if memo2[n-1] == -1:
            memo2[n-1] = r2(n-1) % MOD
        if memo3[n-1] == -1:
            memo3[n-1] = r3(n-1)%MOD
        return (memo2[n-1] + memo3[n-1]) % MOD
        
def r2(n):
    if n == 1:
        return 0
    elif n == 2:
        return 1
    elif n == 3:
        return 1
    else:
        if memo1[n-2] == -1:
            memo1[n-2] = r1(n-2) % MOD
        if memo3[n-2] == -1:
            memo3[n-2] = r3(n-2) % MOD
        return (memo1[n-2] + memo3[n-2]) % MOD

def r3(n):
    if n == 1:
        return 0
    elif n == 2:
        return 0
    elif n == 3:
        return 1
    else:
        if memo1[n-3] == -1:
            memo1[n-3] = r1(n-3) % MOD 
        if memo2[n-3] == -1:
            memo2[n-3] = r2(n-3) % MOD
        return (memo1[n-3] + memo2[n-3]) % MOD



def r(n):
    return (r1(n) + r2(n) + r3(n)) % MOD
for i in range(4,N):
    r(i)

print(r(N))