// CheckNRIC.java
// Aaron Tan
// To determine the check code of a Singapore NRIC number.

import java.util.*;

public class CheckNRIC {
 
   public static void main(String[] args) {

      Scanner stdIn = new Scanner(System.in);

      System.out.print("Enter 7-digit NRIC number: ");
      int numberInput = stdIn.nextInt();
      int number = numberInput; 
  
      // Extract the digits
      int digit7 = number%10;
      number /= 10;
      int digit6 = number%10;
      number /= 10;
      int digit5 = number%10;
      number /= 10;
      int digit4 = number%10;
      number /= 10;
      int digit3 = number%10;
      number /= 10;
      int digit2 = number%10;
      number /= 10;
      int digit1 = number%10;

      int step1 = digit1*2 + digit2*7 + digit3*6 + digit4*5 +
                  digit5*4 + digit6*3 + digit7*2;
      int step2 = step1 % 11;
      int step3 = 11 - step2;

      char checkCode = ' ';
      switch (step3) {
         case 1: checkCode = 'A'; break;
         case 2: checkCode = 'B'; break;
         case 3: checkCode = 'C'; break;
         case 4: checkCode = 'D'; break;
         case 5: checkCode = 'E'; break;
         case 6: checkCode = 'F'; break;
         case 7: checkCode = 'G'; break;
         case 8: checkCode = 'H'; break;
         case 9: checkCode = 'I'; break;
         case 10: checkCode = 'Z'; break;
         case 11: checkCode = 'J';
      }

      System.out.println("Check code for " + numberInput 
                          + " is " + checkCode);
   }

}