def f(n):
    res = 0
    cont_op = 0
    i = n
    while i <= n:
        for j in range(i//2, i*i+1, i+1):
            for k in range(n, 2*n+1, i+1):
                res += n
                cont_op += 1
        i += i//2+1
    return cont_op