#include <stdio.h>

const int max = 1000;
int stack[max];

char rchar()
{
  char c;
  while ( (c = getchar() ) == ' ');
//  printf( "r-%c\n", c);
  return c;
}

int amax(int a, int b)
{
  if ( a > b) return a;
  else return b;
}

int doState( bool comp )
{
  char c;
  
  c = rchar();
  if ( c == EOF) return 0;
  while ( c == 'C' ) 
  {
    comp = !comp;
    c = rchar();
  }
  
  if ( c == 'U' )
  {
    int left, right;
    left = doState( comp );
    right = doState( comp );
    if ( comp ) return amax(left, right);
    else return left + right;
  }
  
//  printf("-%c\n", c);
  
  return 1;
}

int main()
{
  while ( 1 )
  {
    int res;
    res = doState( false);
    if ( !res ) break;
    
    printf( "%d\n", res );
//    printf( "---%c\n", getchar());
    if ( getchar() == EOF ) break;
  }
  return 0;
}