#define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (int)n; i++)
#define repp(i, m, n) for (int i = (int)m; i < (int)n; i++)
#define all(v) begin(v), end(v)
using namespace std;
using ll = long long int;

int main() {
    // 入力
    string S;
    cin >> S;

    // 計算
    int L = S.length(), road = (1 << L);
    rep(i, L) road += (S[i] == 'R' ? (1 << (L - 1 - i)) : 0);

    // 出力
    cout << road << endl;
}