You are given two sorted arrays A[] and B[] of sizes m and n respectively. Write a program to merge them in such a way that the resultant array is sorted too.

**Problem Note**

- The size of the resultant array should be n+m.
- You are expected to solve this question in
**O(n+m)**time. - Your final array should be the first array i.e. array A.

**Example 1**

```
Input: A[] = [3,9,10,18,23], B[] = [5,12,15,20,21,25]
m = 5, n = 6
Output: [3,5,9,10,12,15,18,20,21,23,25]
```

**Example 2**

```
Input: A[] = [2,5,9], B[] = [12,19,23], m = 3, n = 3
Output: [2,5,9,12,19,23]
```

**Example 3**

```
Input: A[] = [2,20], B[] = [5,9,14,16,19], m = 2, n = 5
Output: [2,5,9,14,16,19,20]
```