def func(n):
    sqrt = int(n ** 0.5)
    ans = 0
    ni = 0
    for i in range(1, sqrt):  # how many times the current thing goes in n
        l = n // (i + 1) + 1
        r = n // i
        ans += (r - l + 1) * n - i * (r + 1 - l) * (l + r) // 2
        ni = i + 1
    for x in range(1, n // ni + 1):
        ans += n % x
    return ans