String Explosion

using System;
using System.Text;

namespace String_Explosion
{
    class Program
    {
        static void Main(string[] args)
        {
            StringBuilder input = new StringBuilder();
            input.Append(Console.ReadLine());
            int strength = 0;

            for (int i = 0; i < input.Length; i++)
            {
                if (input[i] == '>')
                {
                    strength += int.Parse(input[i + 1].ToString());

                    if (char.IsLetterOrDigit(input[i + 1]))
                    {

                        for (int j = i + 1; j < i + 1 + strength; j++)
                        {
                            if (strength > input.Length - j - 1)
                            {
                                input.Remove(j, input.Length - j);
                                break;
                            }

                            if (input[j] != '>')
                            {
                                input.Remove(j, 1);
                                strength -= 1;
                                j--;
                            }
                        }

                    }
                }
            }
            Console.WriteLine(input);
        }
    }
}