public class BigInteger {
     // The sign of this integer - true for a positive number, and false
     // otherwise
     private boolean sign = true;
     // digits[0] is the most significant digit of the integer, and
     // the last element of this array is the least significant digit.
     // For example, if we have a BigInteger of value 34, then
     // digits[0] = 3 and digits[1] = 4.
     private byte[] digits;
     private int length;
     public int lengths;
     public BigInteger() {
         this.digits = new byte[1];
         this.digits[0] = 0;
     }
     public BigInteger(byte[] digits) {
         this.digits = digits;
     }
     /**
      * Initializes a <code>BigInteger</code> according to a string. The form of
      * <code>numberStr</code> is a string consisting of all digits ranging from
      * 0 to 9, following an OPTIONAL minus symbol (i.e., "-"). For example,
      * "1234567891234567" and "-17788399934334388347734" are both valid.
      *
      * @param numberStr
      *             a number expressed as a string
      */
     public BigInteger(String numberStr) {
        
        
        
     char[]     num =numberStr.toCharArray();
         int   len=num.length;
         byte[] c=new byte[len];
      for(int i=0;i<len;i++){
          c[i]=Byte.parseByte(String.valueOf(num[i]));
      }
         this.lengths=len;
        
         // YOU FILL THIS IN
         // Note: You should parse the string and initialize the "digits" array
         // properly.
         // You may also need to set the "sign" variable to a correct value.
     }