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

int main(void){
    long ans = 1;
    char s;
    while(1){
        s = getchar();
        if(s=='L'){
            ans *= 2;
        }else if(s=='R'){
            ans = 2*ans + 1;
        }else{
            printf("%ld\n", ans);
            return 0;
        }
    }
}