Softuni Numerals

import java.math.BigInteger;
import java.util.Scanner;


public class P_20160228_SoftuniNumerals {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String letters = scanner.nextLine();
        String number = new String();
        String aa = "aa";
        String cc = "cc";
        for (int i = 0; i < letters.length(); i++) {
            if (letters.substring(i, i+2).equals(aa) || letters.substring(i,i+2).equals(cc)) {
                number += letters.substring(i,i+2).equals(aa) ? "0" : "3";
                i++;
            }else {
                switch (letters.substring(i,i+3)){

                case "aba": number += "1";
                    break;
                case "bcc": number += "2";
                    break;
                case "cdc": number += "4";
                    break;
                }
                i+=2;
            }
        }
        BigInteger format = new BigInteger(number, 5);
        System.out.println(format.toString(10));
    }

}