        . , -
   ,    .

int total = get total from account(); / *    */
int withdrawal = get_withdrawal_amount(); /*  ,

   */

/* ,        */
if (total < withdrawal)

error("    !")

/* ,    :    

     */
total -= withdrawal;

update total funds(total);

/*    */
spit_out money(withdrawal);

 ,            -
     .   ,   -
   . ,      
 ,  -      ,
         - (    
),   - .

 ,     ,  , 
  : ,    ,  
      , ,   .
    . ,   -
   $100,    $10, ,  ,     
(  :   ,     
  ).  ,       , 
$105. ,          
    .

 ,   -  :  -
        .      
$105, ,   $105  $10,    $95,  $10  .
      ,    -
,   $95     $100.

       ,  .
,            
 .   ,     : $105 
  $100   $10.        
$100  $105   $5.          
     $10  $105,   $95.     -
   :     $5.   -
        ,     $95.
   !

      165