#include <stdio.h>


int main(void) {
    char s[31] = "";
    scanf("%s", s);
    int result = 1;
    int i;
    for (i = 0; '\0' != s[i]; i++) {
        result = 2 * result + ('L' == s[i] ? 0 : 1);
    }
    printf("%d\n", result);
    return 0;
}