Perse-script

Two good friends were trying to make a new programming language called Perse-script.

The most important part of this language is strings. A string in Perse-script is put between characters "

So for example "Hello" is a string. But Hello is a variable name or a keyword, which are not considered in this problem.

Perse-script is function-based. So there are no operators in this language. For example for summing two numbers you have to write sum(a,b) and not a+b.

There are several functions for working on strings. These include:

• concat(x,y) is a function which gets two strings x and y and puts y at the end of x and returns the result. For example concat("Hello","World") returns "HelloWorld".
• reverse(x) gets a single string x and reverses it. For example reverse("Hello") returns "olleH".
• substr(x,a,b) gets a string x and two integers a and b (1 ≤ a ≤ b ≤ n, where n is the length of x). And returns the substring of x between indexes a and b, inclusive. For example substr("Hello",2,4) returns "ell".
• substr(x,a,b,c) is another version of substr which works just like the last one but c is the step of adding. c is positive. For example substr("HelloWorld",1,10,2) returns "Hlool". This substr means that you put the ath character , and then every cth character until you reach b.

You're going to manipulate the string part of Perse-script. Given a string expression, you should print its result. It is guaranteed that the expression contains only strings shown by characters " and the above functions.

Commands in Perse-script are case-insensitive. So to call substr function you can write SUBsTr(). But you can't print as the result "hElLo" instead of printing "Hello".

See the samples for more information.