int Led1 = 25;
int Led2= 26;
int Led3 = 27;
void setup() {
  pinMode(Led1,OUTPUT);
  pinMode(Led2,OUTPUT);
  pinMode(Led3,OUTPUT);
}
void loop() {
  digitalWrite(Led1, HIGH);
  delay(1000);
  digitalWrite(Led1, LOW);
  delay(1000);
  digitalWrite(Led2, HIGH);
  delay(1000);
  digitalWrite(Led2, LOW);
  delay(1000);
  digitalWrite(Led3, HIGH);
  delay(1000);
  digitalWrite(Led3, LOW);
  delay(1000);
}