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));