int switchmode=0;
void setup() {
  // initialize digital pin LED_BUILTIN as an output.
  pinMode(21, OUTPUT);//red
  pinMode(19, OUTPUT);//yellow
  pinMode(18, OUTPUT);//green
  pinMode(12,INPUT);
}

// the loop function runs over and over again forever
void loop() {
  switchmode= digitalRead(12);
  if(switchmode==HIGH)
  {
    //R-Y-G
  digitalWrite(21, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);                       // wait for a second
  digitalWrite(21, LOW);    // turn the LED off by making the voltage LOW
  delay(1000); 
  digitalWrite(19, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);                       // wait for a second
  digitalWrite(19, LOW);    // turn the LED off by making the voltage LOW
  delay(1000); 
  digitalWrite(18, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);                       // wait for a second
  digitalWrite(18, LOW);    // turn the LED off by making the voltage LOW
  delay(1000); 

  //G-Y-R
  digitalWrite(18, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);                       // wait for a second
  digitalWrite(18, LOW);    // turn the LED off by making the voltage LOW
  delay(1000); 
  digitalWrite(19, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);                       // wait for a second
  digitalWrite(19, LOW);    // turn the LED off by making the voltage LOW
  delay(1000); 
  digitalWrite(21, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);                       // wait for a second
  digitalWrite(21, LOW);    // turn the LED off by making the voltage LOW
  delay(1000); }
  else  if(switchmode==LOW){
  digitalWrite(21, LOW);    // turn the LED off by making the voltage LOW
  delay(1000); 
  digitalWrite(19, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);                       // wait for a second
  digitalWrite(18, LOW);    // turn the LED off by making the voltage LOW
  delay(1000);

  }
  /*//R-Y-G
  digitalWrite(21, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);                       // wait for a second
  digitalWrite(21, LOW);    // turn the LED off by making the voltage LOW
  delay(1000); 
  digitalWrite(19, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);                       // wait for a second
  digitalWrite(19, LOW);    // turn the LED off by making the voltage LOW
  delay(1000); 
  digitalWrite(18, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);                       // wait for a second
  digitalWrite(18, LOW);    // turn the LED off by making the voltage LOW
  delay(1000); 

  //G-Y-R
  digitalWrite(18, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);                       // wait for a second
  digitalWrite(18, LOW);    // turn the LED off by making the voltage LOW
  delay(1000); 
  digitalWrite(19, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);                       // wait for a second
  digitalWrite(19, LOW);    // turn the LED off by making the voltage LOW
  delay(1000); 
  digitalWrite(21, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);                       // wait for a second
  digitalWrite(21, LOW);    // turn the LED off by making the voltage LOW
  delay(1000); 
  */

}