Convert Binary To Decimal Such As Bin

I am having an issue with my program. It is supposed to convert from a binary number to a decimal number such as bin 101 = dec 5. my first and foremost issue is that when I use System.out.println(parseBin("101")); it returns 5 as it should. However when I change 101 to 1013 it returns 13??? Why is this happening and why are my exceptions not catching the issue?

//import java.util.Scanner;
public class BinaryFormatException {
public static void main(String[] args) throws BinFormatException{
System.out.println(parseBin("1013"));
//Scanner input = new Scanner(System.in);
//System.out.println("Please enter a binary number using 1's and 0's: ");
//String binString = input.nextLine();

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