Requirements 1) read from output file eg: 1222222 + 2333333 3444444 - 9999999 6666555 * 7 0 2) For addition and sutraction, Number1 and Number2 should be large integers and must be stored in a link list. eg.output = 1222222 + 2333333 = 454444444(answer) 3) For multiplication, Number1 should be stored in a link list and the small integer in a variable. output = 66666555 * 7 = 43343555555(answer) 4) Write to output file Code When I try to read from the output file, this error is generated !!Error :Variable last might not have been initialize Help me to clarify the issue becuase i don't think I have to initialize "last" as it has already been declared as a node type. //Jkd1.6.0_02 Code: import java.io.*; import java.util.*; class Node{ int bigInt; Node next; Node(){ bigInt = 0; next = null; } public Node(int bigInt){ bigInt = 0; next = null; } } public class BuildList{ public static void main(String[] args)throws IOException{ Scanner in = new Scanner(new FileReader("input.txt")); FileWriter out = new FileWriter("output.txt") ; Node top, np, last; top = null; //Reading data from input.txt int bigInt = in.nextInt(); while(bigInt!=0){ if (bigInt > 100){//only bigInt numbers are added to the list for add, subtract and multiply np = new Node(bigInt); if (top==null){ top = np; }else{ last.next = np; last = np; bigInt = in.nextInt(); } } } }//end main }//end class check