import std.algorithm, std.array, std.container, std.range;
import std.string, std.conv;
import std.math, std.bigint, std.bitmanip, std.random;
import std.stdio, std.typecons;

void main()
{
  auto s = readln.chomp;

  auto r = reduce!((a, c) => a * 2 + (c == 'L' ? 0 : 1))(1, s);

  writeln(r);
}