#include <stdio.h>

 

int root(int n, char side[]){

              if(n==-1) return 1;

              if(side[n]=='L') return (root(n-1, side)*2);

              if(side[n]=='R') return (root(n-1, side)*2 + 1);

}

 

int main(void) {

              // your code goes here

              int i, n=0;

              char now, lr[255]={};

              scanf("%s",lr);

 

              while(lr[n]!=NULL){

                            n++;

              }

              n--;

              printf("%d",root(n, lr));

              return 0;

}