#include<stdio.h>
#include<string.h>

int main()
{
  int kokudou=1;
  int i;
  char c;
  while(1){
    scanf("%c",&c);
    if(c=='L'){
      kokudou = kokudou*2;
    }
    else if(c=='R'){
      kokudou = kokudou*2 +1;
    }
    else{
      break;
    }
  }
  printf("%d\n",kokudou);
  return 0;
}