#include <algorithm>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <string>
#include <vector>
using namespace std;
typedef long long int ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
#define rep(i,x) for(int i=0;i<(int)(x);++i)

int main(){
	int r = 1;
	string s;
	getline(cin,s);
	rep(i,s.size()) {
		r *= 2;
		if (s[i]=='R') ++r;
	}
	cout << r << endl;
	return 0;
}