46.21

Given an array of size **N** with all initial values as 0, write a program to perform following **M** range increment operations as shown below:** **

```
increment(a, b, k) : Increment values from 'a'
to 'b' by 'k'.
After M operations, calculate the maximum value
in the array.
```

**Input:**

First line of input contains a single integer T which denotes the number of test cases. T test cases follows. First line of each test case contains two space separated integers N and M. Next M lines of each test case contains three space separated integers a , b and k.

**Output:**

For each test case print the maximum element in the array after M increment operations.

**Constraints:**

1<=T<=100

1<=N<=10^{5}

1<=M<=1000

0<= a,b <= N-1

**Example:
Input:**

2

5 3

0 1 100

1 4 100

2 3 100

4 3

1 2 603

0 0 286

3 3 882

200

882