using System;

public class Program

{

    public static void Main()

    {

        string[] a = { "aaa","bbb","ccc","ddd","eee" };

        string b="42531";

        int n = a.Length,i;

        string[] s = new string[n];

        for(i=0;i<n;i++)

        {

            int c=Convert.ToInt32(b[i]);

            s[i]=a[c-49];

        }

        Console.WriteLine("a:[{0}]",string.Join(",",s));

    }

}