Exam 4. Magic Car Numbers (on Java code)

import java.util.Scanner;

public class _4_MagicCarNumbers {

    private static char[] letters = { 'A', 'B', 'C', 'E', 'H', 'K', 'M', 'P',
            'T', 'X' };
    private static int[] weights = { 10, 20, 30, 50, 80, 110, 130, 160, 200,
            240 };

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner scan = new Scanner(System.in);
        int magicWeight = scan.nextInt();

        int countMagicCarNumbers = 0;
        if (magicWeight >= 60 && magicWeight <= 556) {
            magicWeight -= 40;
            countMagicCarNumbers = getCountOfMagicCarNumbers(magicWeight);
        }

        System.out.println(countMagicCarNumbers);
    }

    private static int getCountOfMagicCarNumbers(int magicWeight) {
        int counter = 0;
        int d1, d2, d3, d4, let1, let2;
        for (d1 = 0; d1 <= 9; d1++) {
            for (d2 = 0; d2 <= 9; d2++) {
                for (d3 = 0; d3 <= 9; d3++) {
                    for (d4 = 0; d4 <= 9; d4++) {
                        for (let1 = 0; let1 < letters.length; let1++) {
                            for (let2 = 0; let2 < letters.length; let2++) {
                                int specialWeight = calculateTheWeightOfSpecialMagicNumbers(
                                        d1, d2, d3, d4, let1, let2);
                                if (specialWeight == magicWeight) {
                                    counter++;
                                }
                            }
                        }
                    }
                }
            }
        }

        return counter;
    }

    private static int calculateTheWeightOfSpecialMagicNumbers(int a, int b,
            int c, int d, int x, int y) {
        boolean numberIsSpecial = (b == a && c == a && d == a)
                || (b != a && c == b && d == b) || (b == a && c == a && d != a)
                || (b == a && c != a && d == c) || (b != a && c == a && d == b)
                || (b != a && c == b && d == a);

        int weight = 0;
        if (numberIsSpecial) {
            weight = a + b + c + d + weights[x] + weights[y];
        }

        return weight;
    }

}