#include #define rep(i, a, n) for (int i = a; i < n; i++) #define repr(i, a, n) for (int i = n - 1; i >= a; i--) using namespace std; using ll = long long; using P = pair; template void chmin(T &a, T b) { a = min(a, b); } template void chmax(T &a, T b) { a = max(a, b); } int main() { ios::sync_with_stdio(false); cin.tie(0); string s; cin >> s; int ans = 1; rep(i, 0, s.size()) { ans *= 2; if (s[i] == 'R') ans++; } cout << ans << endl; }