using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public class Res{

    public string Key;

    public int Val;

}

    public static void Main()

    {

        var locationOutputDistinct = new List<string>

{

"PERSON:2 ",

"PERSON:1 SCOOTER:1 ",

"PERSON:1 BIKE:1 ",

"PERSON:2 BIKE:1 ",

"PERSON:1 BIKE:1 SCOOTER:1 ",

"PERSON:3 ",

"PERSON:3 BIKE:1 ",

"PERSON:4 ",

"PERSON:4 BIKE:1 ",

"PERSON:2 SCOOTER:1 ",

"PERSON:5 ",

"PERSON:3 SCOOTER:1 ",

"PERSON:6 "

};

         var loc =  

        locationOutputDistinct

        .Select(x => x.Trim().Split(' ')

        .Select(

            y => {

                var kv = y.Split(':');

                return new Res()

                {   Key = kv[0],

                    Val = int.Parse

                     (kv[1])

                };}))

​

         .GroupBy(x =>

            String.Join(",",

            x.Select(y => y.Key))

            );

        foreach(var x in loc)

          Console.WriteLine

          (//x.Key+": " +

            String.Join(",",

            x.SelectMany(y => y

                .GroupBy(w => w.Key)

                .Select(w => new Res()

                    {

​

                     Key =

                     w.Select(z => z.Key).First()

                     , Val =

                     w.Max(z => z.Val)

                    }) 

​

​

                )

​

                    .GroupBy(q => q.Key)

                   .Select(z => 

                    z.Key +"="+

                    z.Max(q => q.Val))

​

            ));

    }

}