using System;

using System.Text.RegularExpressions;

using System.Linq;

​

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        string Input = "....Thalassius! vero ea--*/-*/-- tempestate+- fectus";

        string Output = Input;

        var regex = new Regex(@"[^\w\s]|_");

        var matches = regex.Matches(Input) ;

        var MatchesIndex = matches  .Cast<Match>()

                                    .Select(match => match.Index)

                                    .ToArray();

        int last = 0;

        List<int> toDelete = new List<int>();

        for (int i = 0; i < MatchesIndex.Length; i++)

        {

            if ( MatchesIndex[i] == last + 1)

                toDelete.Add(MatchesIndex[i]);

            last = MatchesIndex[i];

        }

        foreach (int i in toDelete.OrderByDescending(x => x))

            Output = Output.Remove(i, 1);

        Console.WriteLine("Input : " + Input);

        Console.WriteLine("Output : " + Output);

    }

}