using System;
using System.Linq;
using System.Collections.Generic;
 
public class Test
{
	public static void Main()
	{
var dict = new Dictionary<String, List<String>>() { 
    {"1",new List<String>(){"a", "b"}},
    {"2",new List<String>(){"c", "d", "e"}},
    {"3",new List<String>(){"f", "g", "h"}},
};
var result = from kv in dict
             from val1 in kv.Value
             from val2 in kv.Value
             select string.Format("{0}{1}", val1, val2);
 
int combiCount = 0;
foreach (var combi in result)
    Console.WriteLine(++combiCount +". " + combi);
 
	}
}

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