#include <bits/stdc++.h>
#define FOR(i,a,b) for(int i = (a); i < (b); ++i)
#define REP(i,n) FOR(i,0,n)
#define sz(n) (int)(n).size()
using namespace std;
typedef long long ll;

int main() {
	string s;
	cin >> s;
	int ans = 1;
	for (int i = 0; s[i] != '\0'; ++i) {
		ans += ans;
		if (s[i] == 'R') ans++;
	}
	cout << ans << endl;
	return 0;
}