**Time limit:**1.00 s**Memory limit:**512 MB

You can modify the array using the following operation: choose an array element and increase its value by one.

Your task is to process $q$ queries of the form: when we consider a subarray from position $a$ to position $b$, what is the minimum number of operations after which the subarray is increasing?

An array is increasing if each element is greater than or equal with the previous element.

**Input**

The first input line has two integers $n$ and $q$: the size of the array and the number of queries.

The next line has $n$ integers $x_1,x_2,\dots,x_n$: the contents of the array.

Finally, there are $q$ lines that describe the queries. Each line has two integers $a$ and $b$: the starting and ending position of a subarray.

**Output**

For each query, print the minimum number of operations.

**Constraints**

- $1 \le n,q \le 2\cdot10^5$

- $1 \le x_i \le 10^9$

- $1 \le a \le b \le n$

**Example**

Input:

`5 3`

2 10 4 2 5

3 5

2 2

1 4

Output:

`2`

0

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