int led_red = 23;
int led_yellow = 19;
int led_green = 18;
// I have avariable name led_red
// Its value is 23
// I have avariable name led_yellow
// Its value is 19
// I have avariable name led_green
// Its value is 18

void setup() {
 // put your setup code here, to run once:
 pinMode(led_red, OUTPUT);
 pinMode(led_yellow, OUTPUT);
 pinMode(led_green, OUTPUT);

 Serial.begin(9600);

Serial.println("Testing 1!");
}

void loop() {
 // put your main code here, to run repeatedly:
 digitalWrite(led_red, HIGH);
 digitalWrite(led_yellow, HIGH);
 digitalWrite(led_green, HIGH);
 delay(200);

 digitalWrite(led_red, LOW);
 digitalWrite(led_yellow, LOW);
 digitalWrite(led_green, LOW);
 delay(200);
}