// Which pins are connected to which LED
const byte LED1 = 6;
const byte LED2 = 7;
const byte LED3 = 8;
const byte LED4 = 9;
const byte LED5 = 10;
const byte LED6 = 11;
 
 
// Assigning delays.
const unsigned long LED1_ON_interval = 15000; //
const unsigned long LED1_OFF_interval = 15000;
const unsigned long LED2_ON_interval = 16000; //
const unsigned long LED2_OFF_interval = 16000;
const unsigned long LED3_ON_interval = 450000; //
const unsigned long LED3_OFF_interval = 450000;
const unsigned long LED4_ON_interval = 1000; //
const unsigned long LED4_OFF_interval = 1000;
const unsigned long LED5_ON_interval = 48000; //
const unsigned long LED5_OFF_interval = 48000;
const unsigned long LED6_ON_interval = 50000; //
const unsigned long LED6_OFF_interval = 50000;
 
 
// Declaring the variables holding the timer values for each LED.
unsigned long LED1_timer;
unsigned long LED2_timer;
unsigned long LED3_timer;
unsigned long LED4_timer;
unsigned long LED5_timer;
unsigned long LED6_timer;
 
  
 
// Setting 3 digital pins as output pins and resetting timer
void setup ()
  {
  pinMode (LED1, OUTPUT);
  pinMode (LED2, OUTPUT);
  pinMode (LED3, OUTPUT);
  pinMode (LED4, OUTPUT);
  pinMode (LED5, OUTPUT);
  pinMode (LED6, OUTPUT);
  LED1_timer = millis ();
  LED2_timer = millis ();
  LED3_timer = millis ();
  LED4_timer = millis ();
  LED5_timer = millis ();
  LED6_timer = millis ();
  }  // end of setup
 
 
//LED1 loop that turns it ON if it is OFF and vice versa
void toggle_LED1 ()
  {
   if (digitalRead (LED1) == LOW)
      digitalWrite (LED1, HIGH);
   else
      digitalWrite (LED1, LOW);
 
 
  // remember when we toggled it
  LED1_timer = millis (); 
  }  // end of toggleLED_1
 
 
//LED2 loop
void toggle_LED2 ()
  {
   if (digitalRead (LED2) == LOW)
      digitalWrite (LED2, HIGH);
   else
      digitalWrite (LED2, LOW);
 
 
  // remember when we toggled it
  LED2_timer = millis (); 
  }  // end of toggle_LED2
 
  //LED 3 loop
void toggle_LED3 ()
  {
   if (digitalRead (LED3) == LOW)
      digitalWrite (LED3, HIGH);
   else
      digitalWrite (LED3, LOW);
 
 
  // remember when we toggled it
  LED3_timer = millis (); 
  }  // end of toggle_LED3
  
  void toggle_LED4 ()
  {
   if (digitalRead (LED4) == LOW)
      digitalWrite (LED4, HIGH);
   else
      digitalWrite (LED4, LOW);
 
 
  // remember when we toggled it
  LED4_timer = millis (); 
  }  // end of toggleLED_4
 
 
//LED2 loop
void toggle_LED5 ()
  {
   if (digitalRead (LED5) == LOW)
      digitalWrite (LED5, HIGH);
   else
      digitalWrite (LED5, LOW);
 
 
  // remember when we toggled it
  LED5_timer = millis (); 
  }  // end of toggle_LED5
 
  //LED 3 loop
void toggle_LED6 ()
  {
   if (digitalRead (LED6) == LOW)
      digitalWrite (LED6, HIGH);
   else
      digitalWrite (LED6, LOW);
 
 
  // remember when we toggled it
  LED3_timer = millis (); 
  }  // end of toggle_LED6
 
 
void loop ()
  {
 
 
  // Handling the blink of LED1.
  if ( (millis () - LED1_timer) >= LED1_ON_interval)
     toggle_LED1 ();
     // Handling the blink of LED1.
  if ( (millis () - LED1_timer) >= LED1_OFF_interval)
     toggle_LED1 ();
 
 
  // Handling the blink of LED2.
  if ( (millis () - LED2_timer) >= LED2_ON_interval)
    toggle_LED2 ();
     if ( (millis () - LED2_timer) >= LED2_OFF_interval)
    toggle_LED2 ();
   
// Handling the blink of LED3.
  if ( (millis () - LED3_timer) >= LED3_ON_interval)
    toggle_LED3 ();
    
      // Handling the blink of LED4.
  if ( (millis () - LED4_timer) >= LED4_ON_interval)
     toggle_LED4 ();
 
 
  // Handling the blink of LED5.
  if ( (millis () - LED5_timer) >= LED5_ON_interval)
    toggle_LED5 ();
   
// Handling the blink of LED6.
  if ( (millis () - LED6_timer) >= LED6_ON_interval)
    toggle_LED6 ();
   
/* Other code that needs to execute goes here.
   It will be called many thousand times per second because the above code
   does not wait for the LED blink interval to finish. */
 
 
}  // end of loop