נתונות שלוש הפעולות One, Two, Three.

public static string One(string s, char ch)
{
    int i = 0;
    while (i < s.Length && s[i] != ch)
    {
        i++;
    }
    if (i < s.Length)
        s = s.Substring(0, i) + s.Substring(i + 1) + ch;
    return s;
}

public static string Two(string s1, string s2)
{
    while (s1.Length > 0)
    {
        s2 = One(s2, s1[0]);
        s1 = s1.Substring(1);
    }
    return s2;
}

public static bool Three(string s1, string s2)
{
    s2 = Two(s1, s2);
    return s2.Equals(s1);
}