Following is the mergeWords function.

```
mergeWords [] [] = []
mergeWords [] (y:ys) = y:'\n':(mergeWords [] ys)
mergeWords (x:xs) [] = x:'\n':(mergeWords xs [])
mergeWords (x:xs) (y:ys) = x:y:'\n':(mergeWords xs ys)

```

If applied on `mergeWords "hello" "world"` it gives 

```
"hw\neo\nlr\nll\nod\n"

```

I can't figure out how to extend this to list of strings. Like applying it to 3 strings should first take first character of each of the strings and then put a '\n' and then the second character and so on.