// route 1 left 2 right 3
// route 2 left 4 right 5
// route 3 left 6 right 7
// route 4 left 8 right 9
// route 5 left 10 right 11
#include <stdio.h>
int main(void){
	char S[31];		//	0 <= S <= 30
	int route = 1;
	
	scanf("%s",S);
//	printf("%s\n",S);		//	check
	
	for(int i = 0;S[i] != 0;i++){
		route *= 2;
		if(S[i] == 'R'){
			route += 1;
		}
	}
	
	printf("%d",route);
	
	return 0;	
}