#include<stdio.h>


int main(void){

char S;

int i,road=1;



i=0;
for(;;){
	if((S = getchar()) != '\n'){
		if(S=='R')

			road = 2*road + 1;

		else if(S=='L')
			
road = 2*road;

		}else	break;
}

printf("%d\n",road);


return 0;



}