def one(n):
    k=n//3
    return 3*k*(k+1)//2-2*k
def two(n):
    k=n//3
    return 3*k*(k+1)*(2*k+1)//2-3*k*(k+1)+k
def three(n):
    k=n//3
    return 27*(k*(k+1)//2)**2

N=int(input())
res=0
for i in range(1,N+1):
    if i%3==1:
        res+=i
    elif i%3==2:
        res+=i*i
    else:
        res+=i*i*i
print(res)