#include <stdio.h>
int main(){
  int n=0, a=0, b=2;
  char s[51];
  scanf("%s",s);
  while(s[++n]!='\0');
  n--;
  while(n>0){
    a += s[n] == 'u'? b : 0;
    b*=2;
    n -= s[n] == 'u'? 4 : 3;
  }
  printf("%d\n", a);
  return 0;
}