CF444C.DZY Loves Colors

DZY loves colors, and he enjoys painting.

On a colorful day, DZY gets a colorful ribbon, which consists of n units (they are numbered from 1 to n from left to right). The color of the i-th unit of the ribbon is i at first. It is colorful enough, but we still consider that the colorfulness of each unit is 0 at first.

DZY loves painting, we know. He takes up a paintbrush with color x and uses it to draw a line on the ribbon. In such a case some contiguous units are painted. Imagine that the color of unit i currently is y. When it is painted by this paintbrush, the color of the unit becomes x, and the colorfulness of the unit increases by |x - y|.

DZY wants to perform m operations, each operation can be one of the following:

1. Paint all the units with numbers between l and r (both inclusive) with color x.
2. Ask the sum of colorfulness of the units between l and r (both inclusive).

Can you help DZY?

DZY 喜欢颜色，也喜欢绘画。

在一个色彩缤纷的日子里，DZY 得到了一条由 $n$ 个单位组成的彩色丝带（从左到右依次编号为 $1$ 到 $n$）。最初，第 $i$ 个单位的颜色为 $i$。这已经足够绚丽了，但我们仍认为每个单位初始的“绚丽度”（colorfulness）均为 $0$。

我们都知道 DZY 热爱绘画。他拿起一支颜色为 $x$ 的画笔，在丝带上作画——此时若干连续的单位会被涂上该颜色。假设当前单位 $i$ 的颜色为 $y$，那么当它被这支画笔涂色后，其颜色将变为 $x$，且其绚丽度将增加 $|x - y|$。

DZY 想要执行 $m$ 次操作，每次操作为以下两种之一：

1. 将编号在 $l$ 到 $r$（含端点）之间的所有单位涂成颜色 $x$；
2. 查询编号在 $l$ 到 $r$（含端点）之间的所有单位的绚丽度之和。

你能帮帮 DZY 吗？

The first line contains two space-separated integers n, m (1 ≤ n, m ≤ 105).

Each of the next m lines begins with a integer type (1 ≤ type ≤ 2), which represents the type of this operation.

If type = 1, there will be 3 more integers l, r, x (1 ≤ l ≤ r ≤ n; 1 ≤ x ≤ 108) in this line, describing an operation 1.

If type = 2, there will be 2 more integers l, r (1 ≤ l ≤ r ≤ n) in this line, describing an operation 2.

第一行包含两个以空格分隔的整数 $n$、$m$（$1 \le n, m \le 10^5$）。

接下来的 $m$ 行中，每行以一个整数 $\textit{type}$（$1 \le \textit{type} \le 2$）开头，表示该操作的类型。

若 $\textit{type} = 1$，则该行还会包含另外三个整数 $l$、$r$、$x$（$1 \le l \le r \le n$；$1 \le x \le 10^8$），描述操作 1。

若 $\textit{type} = 2$，则该行还会包含另外两个整数 $l$、$r$（$1 \le l \le r \le n$），描述操作 2。

For each operation 2, print a line containing the answer — sum of colorfulness.

对于每个操作 2，输出一行，包含答案——即色彩度之和。

In the first sample, the color of each unit is initially [1, 2, 3], and the colorfulness is [0, 0, 0].

After the first operation, colors become [4, 4, 3], colorfulness become [3, 2, 0].

After the second operation, colors become [4, 5, 5], colorfulness become [3, 3, 2].

So the answer to the only operation of type 2 is 8.

在第一个样例中，每个单位的初始颜色为 [1, 2, 3]，对应的色彩度为 [0, 0, 0]。

第一次操作后，颜色变为 [4, 4, 3]，色彩度变为 [3, 2, 0]。

第二次操作后，颜色变为 [4, 5, 5]，色彩度变为 [3, 3, 2]。

因此，唯一一次类型 2 操作的答案为 8。