#include <stdio.h>
int main(void){
    char route[31];
    long pos = 1;
    scanf( "%s", route );
    for( int i = 0; i < 30; i++ ){
        if( route[i] == 'L' ){
            pos = pos * 2;
        }else if( route[i] == 'R' ){
            pos = pos * 2 + 1;
        }else{
            break;
        }

    }
    printf( "%ld\n", pos );
}