#include <iostream>
#include<string>
using namespace std;

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