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 a th character , and then every c th 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. A single line containing the correct expression. It is guaranteed that the total length of this expression does not exceed 10 3 and that all the integers used in it are less than or equal to 100 by absolute value. The given string is non-empty. All strings