#include <iostream>
#include <string>

using namespace std;
#define REP(i,n) for (int i=0;i<(n);i++)

int main()
{
	int r = 1;
	string str;
	getline(cin, str);

	REP(i, str.size())
		r = 2 * r + (str[i] == 'L' ? 0 : 1);

	cout << r << endl;

	return 0;
}