How do i improve my typing speed in just four days,from 20 wpm to 45 wpm?

This is the best exercise ever for increasing your typing speed. only type following sentence.

That the quick brown fox jumps over the lazy dog. 

daily two to three hours using proper fingers for alphabets 

type this sentence daily 100 times---> that the quick brown fox jumps over the lazy dog.<------ because alphabet A to Z is present in this sentence 

Better memorise the characters, improve reading speed. Repeat typing as !any times as possible.

Hi. sorry for the delay response. you better memorize the qwerty position keys and u need exercises using typing test. don't cheat so will learn from it

TYPING SKILLS INCREASE THAT  EXERCISE

THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG 

ALL ALPHABETS IS INCLUDING IN ONE LINE

use Typing master Software