using System;

public class Program

{

    public static void Main()

    {

        int[] arrayA = {'a','b','c'};

        int[] arrayB = {'1','2','3','4'};

        int[] concade = new int [arrayA.Length + arrayB.Length ];

        int j = 0, k = 0,  l = 0;

        int max = Math.Max(arrayA.Length,arrayB.Length);

        for (int i = 0; i< max; i++){

        if(j < arrayA.Length)

            concade[l++] = arrayA[j++];

        if(k < arrayB.Length)

            concade[l++] = arrayB[j++]; 

        }

        System.out.println(Arrays.toString(concade));

    }

}