Click numbers 1 to 25 in sequence. If you missed a number, then blink would stop responding. 
                
                
                    
                    |  |  | 7 |  |  |  | 14 | 23 |  |  | 
|  |  |  |  |  |  |  |  |  | 10 | 
|  |  |  |  |  |  |  | 2 | 12 |  | 
| 8 |  |  |  |  |  |  |  |  |  | 
|  |  |  | 11 |  | 3 |  |  |  |  | 
|  | 25 |  | 16 | 19 | 1 |  |  | 20 | 6 | 
| 4 |  |  |  |  |  |  | 15 |  |  | 
|  |  |  | 22 |  |  |  |  |  |  | 
|  | 17 | 21 |  |  | 9 |  | 24 |  |  | 
|  | 18 | 13 | 5 |  |  |  |  |  |  | 
                
            
            
                
            Time = 0  sec.
               
            
            
            
            
            
                 
                (  
                     
 
                     
                     Tested on Windows 10. Should work on other platforms as well. 
                )
                     
                    Tested on Windows 10. Should work on other platforms as well. 
                )
            
        
        
        
            
    
    
      
        
        
            
            
                
            
            
            
                    Last modified at Feb 1. 2021