using System;
using System.Collections.Generic;
using System.Linq;

namespace No104
{
	class MainClass
	{
		private static long LeftPosition(int length)
		{
			long index = 1;
			for (int i = 0; i < length; i++) {
				index *= 2;
			}
			return index;
		}

		public static void Main (string[] args)
		{			
			var s = Console.ReadLine ();
			if (s.Length == 0) {
				Console.WriteLine ("1");
				return;
			}
			var leftPosition = LeftPosition (s.Length);
			var length = leftPosition / 2L;
			for (int i = 0; i < s.Length; i++) {
				if (s [i] == 'R') {
					leftPosition += length;
				} 
				length /= 2L;
			}
			Console.WriteLine (leftPosition.ToString());
		}
	}
}