Generate two different strings with the same hashcode

Finding two strings by repeatedly comparing random strings will take practically forever. Instead generate strings and store them in an a dictionary by hashcode. Then look up each. Match found pretty quickly.

MATCH FOUND!! xqzrbn and krumld hash code 80425224

void Main()
{

    var lookup = new Dictionary<int,string>();

    while(true) {
        var s = RandomString();        
        var h = s.GetHashCode();
        string s2;
        if (lookup.TryGetValue(h, out s2) && s2 != s) {
            Console.WriteLine("MATCH FOUND!! {0} and {1} hash code {2}",
                lookup[h],
                s,
                h);
            break;
        }
        lookup[h] = s;

        if (lookup.Count % 1000 == 0) {
            Console.WriteLine(lookup.Count);
        }
    }
}

static Random r = new Random();

// Define other methods and classes here
static string RandomString() {

    var s = ((char)r.Next((int)'a',((int)'z')+1)).ToString() +
            ((char)r.Next((int)'a',((int)'z')+1)).ToString() +
            ((char)r.Next((int)'a',((int)'z')+1)).ToString() +
            ((char)r.Next((int)'a',((int)'z')+1)).ToString() +
            ((char)r.Next((int)'a',((int)'z')+1)).ToString() +
            ((char)r.Next((int)'a',((int)'z')+1)).ToString();

    return s;
}