# How to Process the Multiline input in Node JS

Yet again as always while trying to solve the problem statement, logically I can easily do that but again I got lost on how to do the input processing. No idea let's look at it.

For example, suppose the Elves finish writing their items' Calories and end up with the following list:

```xml
1000
2000
3000

4000

5000
6000

7000
8000
9000

10000
```

Data is just like that for each elves.

*   The first Elf is carrying food with `1000`, `2000`, and `3000` Calories, a total of `6000` Calories.
    
*   The second Elf is carrying one food item with `4000` Calories.
    
*   The third Elf is carrying food with `5000` and `6000` Calories, a total of `11000` Calories.
    
*   The fourth Elf is carrying food with `7000`, `8000`, and `9000` Calories, a total of `24000` Calories.
    
*   The fifth Elf is carrying one food item with `10000` Calories.
    

So I have to take out that fourth elf which has the 24000 cal and print it. I don't know how to process the file.

Let's look at the basics,

```javascript
const fs = require('fs');

fs.readFile('./input.txt', 'utf8', (err, data) => {
  if (err) {
    throw err;
  }

  console.log(data);
});
```

So this code does the basic of taking all the data from the file and printing it on the console. This code is not really doing much, using the `fs` module of Node.js and its API to do file processing. If file is not found then it throws the error. Simple nothing much. Now I have to do something to group the data before the blank line.

Here is something like this for that thing.

```javascript
let data = `1000
2000
3000

4000

5000
6000

7000
8000
9000

10000`;

let calories_list = data.split('\n\n').map(lines => {
  return lines.split('\n').reduce((sum, line) => {
    return sum + Number(line);
  }, 0);
});

console.log(calories_list);
```

In this code, the `split` method is used to divide the `data` string into an array of lines, with each element of the array representing a section of the data separated by two newline characters. The `map` method is then used to iterate over this array of lines, and for each element (which represents a section of the data separated by blank lines), the `split` method is used again to split the element into an array of individual lines.

The `reduce` method is then called on this array of lines, with the `sum` parameter representing the sum of the numbers on the lines, and the `line` parameter representing the current line being processed. For each line, the `reduce` method adds the number on the line to the `sum` variable, and returns the updated `sum` value. This process is repeated for each line in the array, and the final `sum` value is returned as the result of the `map` callback.

The resulting array of sums is then assigned to the `calories_list` variable, and the code logs this array to the console. The output is `[6000, 4000, 11000, 24000, 10000]`, which are the sums of the numbers in each section of the data separated by blank lines.

Then all that is left is do these and it will provide the output as.

```javascript
const sol1 = Math.max(...calories_list);
console.log(sol1);
```