using System;
using System.IO;
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
letters_2();
}
private static void letters_2()
{
string s = "abcdefghijklmnopqrstuvwxyz", w;
StreamWriter sw = File.CreateText(@"d:\2letters-combination.txt");
for (int i = 0; i < s.Length; i++)
{
for (int j = 0; j < s.Length; j++)
{
w = s[i].ToString() + s[j].ToString();
sw.WriteLine(w);
}
}
sw.Close();
}
}
}