java - How to extract the digits and multiply it? -

I'm partially with Lohan Formula. I just want to understand it with my understanding so that I I can understand how it has been executed well but I have a problem in multiplying the number (number) by 2.

  string input = "1234567890123456"; String reverse = new stringbuffer (input). Reverse (). ToString (); String A = ""; String c = ""; String result = ""; For (int i = 0; i & lt; = revers.length () - 1; i + = 2) {a + = reverse Chat (i); Int intValue = integer.percent (a); If for (intValue * intValue> 9) {}} (int i = 1; i & lt; = revers.length () - 1; i + = 2) {c + = reverse. Chat (i); }  

a = for each number in reverse variable c =