github.com/captn3m0/codechef.git

---
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---
<span class="solution-visible-txt">All submissions for this problem are available.</span><p>Alice has <b>N</b> pieces of paper.
These papers are numbered from <b>1</b> to <b>N</b>.
She writes down the numbers <b>1</b> to <b>N</b> in order (one number on each paper),
i.e. paper <i>i</i> has number <i>i</i> written on it.
Bob messes the numbers on these papers.
He either <b>adds</b> a constant to a number or <b>subtracts</b> a constant from the number.
He performs <b>M</b> such operations.
Each operation is of the form: <b>w x y z</b> where each of them is an integer.
If <b>w = 1</b>, then Alice has to <b>add z</b> to every number on papers <b>x</b> to <b>y</b> (<i>both inclusive</i>).
If <b>w = 2,</b> then Alice has to <b>subtract z</b> from every number on papers <b>x</b> to <b>y</b> (<i>both inclusive</i>).
After doing this, Bob challenges Alice to tell him the range of this data,
where <i>range</i> denotes the count of numbers from the smallest number to the largest (See <a href="http://www.wikihow.com/Find-the-Range-of-a-Data-Set">here</a> for more details).
Your task is to help Alice in finding the range.</p>

<h3>Input:</h3>
<p>First line of input contains a single integer <b>T</b>, the number of test cases.<br />
Each test case starts with a line containing two space separated integers <b>N</b> and <b>M</b>.<br />
Then follow <b>M</b> lines. Each of these lines is of the form <b>w x y z</b>. Each separated by a single space.<br /></p>

<h3>Output:</h3>
<p>For each test case output a single line containing the range of the new data set after Bob's modifications.

<h3>Constraints:</h3>
<pre>1 ≤ T ≤ 20
1 ≤ M ≤ 10000
1 ≤ N ≤ 1000000
1 ≤ x ≤ y ≤ N
0 ≤ z ≤ 100000</pre>

<h3>Example:</h3>
<pre>
<b>Input</b>
1
10 2
2 3 6 4
1 5 9 1

<b>Output:</b>
11

</pre>
<b>Explanation:</b> Initially the papers are as follows: 1 2 3 4 5 6 7 8 9 10. First operation decreases the numbers on paper number 3,4,5 and 6 by 4. Now, the papers look like: 1 2 -1 0 1 2 7 8 9 10. The second operation increases the numbers on papers 5 to 9 by 1. The numbers will now be 1 2 -1 0 2 3 8 9 10 10. Thus, the range is 10 - (-1) = 11.</p>