import extensions;
import system'routines;
import system'collections;

extension op
{
    get DigitalRoot()
    {
        int  additivepersistence := 0;
        long num := self;

        while (num > 9)
        {
            num := num.Printable.toArray().selectBy:(ch => ch.toInt() - 48).summarize(new LongInteger());

            additivepersistence += 1
        };

        ^ new Tuple<int,int>(additivepersistence, num.toInt())
    }
}

public program()
{
    new long[]::(627615l, 39390l, 588225l, 393900588225l).forEach:(num)
    {
        var t := num.DigitalRoot;

        console.printLineFormatted("{0} has additive persistence {1} and digital root {2}", num, t.Item1, t.Item2)
    }
}