Untitled

#define led1 2
int led2 =3;
const int led3=4;
void setup() {
  // put your setup code here, to run once:
pinMode(led1, OUTPUT);
pinMode(led2, OUTPUT);
pinMode(led3, OUTPUT);
}
void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(led1, HIGH);
delay(3000);
digitalWrite(led1, LOW);
digitalWrite(led2, HIGH);
delay(3000);
digitalWrite(led2, LOW);
digitalWrite(led3, HIGH);
delay(3000);
digitalWrite(led3, LOW);
}