#include <iostream>

using namespace std;

int main(void){
	string s;
	cin >> s;
	int a = 1;
	for(int i=0;i<s.size();i++){
		if(s[i] == 'L'){
			a *= 2;
		}else{
			a = a * 2 + 1;
		}
	}
	cout << a << endl;
	return 0;
}