Problem:
Reverse Sequence

Write a program which reverses a given string str.

Input

str (the size of str ≤ 20) is given in a line.

Output

Print the reversed str in a line.

Sample Input

w32nimda

Output for the Sample Input

admin23w

Solution in C# (judge verdict: Accepted)

using System;
using System.Collections.Generic;
using System.Text;
namespace ReverseSequence
{
    class Program
    {
        static void Main(string[] args)
        {
            var sb = new StringBuilder();
            var stk = new Stack<char>();
            string str = Console.ReadLine();
            for (int i = 0; i < str.Length; i++)
            {
                stk.Push(str[i]);
            }
            for (int i = 0; i < str.Length; i++)
            {
                sb.Append(stk.Pop());
            }
            
            Console.WriteLine(sb);
        }
    }
}