foreach $value (@num_value) 
            {
                if ($value<$cut_off)
                {     
                    pop(@num_value);                                  
+                  
                }else{
                    last;
                }    
            }
        $sub1=substr($dna,-@num_value); 
        
        @qscopy=reverse @num_value;
        
        foreach $value (@qscopy) 
            {
                if ($value<$cut_off)
                {
                    pop(@qscopy); 
                }else{
                    last;                            
                }
            }