write problem;
think about problem's answer;
if problem's answer exist;
→exist;
   
   write answer;
→no exist;
   
   sleep;
   
   think problem's answer;
   
   if problem's answer exist;
   →exist;
      
      write answer;
   →no exist;
      
      send signal'001
signal'001 sent;
sleep;
think problem's answer;
if problem's answer exist;
→exist;
   
   write answer;
→no exist;
   
   send signal'001;