C#Exams 4. Crossing Sequences (on Java Code)

import java.util.ArrayList;
import java.util.Scanner;

public class _4_CrossingSequences {

    private final static int MaxNum = 1000000;

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner scan = new Scanner(System.in);
        int tribNum1 = scan.nextInt();
        int tribNum2 = scan.nextInt();
        int tribNum3 = scan.nextInt();
        int startNum = scan.nextInt();
        int step = scan.nextInt();

        boolean foundBothSeqNumber = false;
        if (startNum != tribNum1 && startNum != tribNum2
                && startNum != tribNum3) {
            ArrayList<Integer> tribSeq = calculateAndCreateTribonacciSequence(
                    tribNum1, tribNum2, tribNum3);
            foundBothSeqNumber = findHasNumberInBothSequencesAndPrintHim(
                    startNum, step, foundBothSeqNumber, tribSeq);

        } else {
            foundBothSeqNumber = true;
            System.out.println(startNum);
        }

        if (!foundBothSeqNumber) {
            System.out.println("No");
        }
    }

    private static boolean findHasNumberInBothSequencesAndPrintHim(int start,
            int step, boolean foundBothSeqNumber, ArrayList<Integer> tribSeq) {
        int spiralNum = start;
        int counter = 1;
        while (spiralNum <= MaxNum) {
            if (tribSeq.contains(spiralNum)) {
                foundBothSeqNumber = true;
                System.out.println(spiralNum);
                break;
            }

            spiralNum += step * (counter / 2);
            counter++;
        }
        return foundBothSeqNumber;
    }

    private static ArrayList<Integer> calculateAndCreateTribonacciSequence(
            int trib1, int trib2, int trib3) {
        // TODO Auto-generated method stub
        ArrayList<Integer> tribonacci = new ArrayList<Integer>();
        tribonacci.add(trib1);
        tribonacci.add(trib2);
        tribonacci.add(trib3);
        int tribN = 0;
        do {
            tribN = trib1 + trib2 + trib3;
            trib1 = trib2;
            trib2 = trib3;
            trib3 = tribN;
            if (tribN <= MaxNum) {
                tribonacci.add(tribN);
            }
        } while (tribN < MaxNum);

        return tribonacci;
    }
}