Output Specification:

Return the final string Ralph typed.

Example $1$:

input$1$: aa

input$2$: wabsbdwasbajsud

input$3$: $1$

Output: aaab

Explanation:

First, Ralph typed aa as the initial string, then as the operation was $w,$ he typed the

characters which appeared in the operation string, until he was given the next operation.

So he typed: aaabsb.

Next, he had to delete $1$ character, so he deleted $\text{'}$b$\text{'}$ to get: aaabs.

For the next operation, again he had to type characters and so he wrote: aaabsasbajs.

Next, he had to perform undo, which meant he got aaabs and finally he deleted $1$

character to get aaab.

Example $2$:

input$1$: bbhfg

input$2$: wbsydwtreaxcbuwsasxasdRalph and Typing Test

Ralph is learning how to type fast and use some of the shortcuts provided by the

keyboard such as undoing a previous operation, copy$-$pasting and cut$-$pasting. Now, he

has completed the course and is appearing for his final exam. In the exam, he is given

some operations to perform over a string.

He is given two strings, one he has to type and the other string is the operations that he

has to perform. The three major operations that he needs to perform are:

If the operation is $w,$ he has to type in the next characters in the operation string until

the next operation is encountered.

If the operation is $d,$ he has to delete $\text{'}N\text{'}$ characters which he last typed.

If the operation is $u,$ he has to undo the last operation he performed.

You have to find the final string which was typed by Ralph.

Input Specification:

input$1$: The initial string Ralph had to type

input$2$: The operation string

input$3$: $\text{'}N\text{'},$ used in operation $2$

Output Specification:

Return the final string Ralph typed.