int LED1=2;
int LED2=3;
int LED3=4;
int BOTON=5;

void setup()
{
  pinMode(LED1, OUTPUT);
  pinMode(LED2, OUTPUT);
  pinMode(LED3, OUTPUT);
  pinMode(BOTON, INPUT);
}

void loop(){
 if (digitalRead(BOTON)==LOW)
 {
    digitalWrite(LED1, HIGH); 
    delay(1000);
    digitalWrite(LED1, LOW);
    digitalWrite(LED2, HIGH);
    delay(1000);
    digitalWrite(LED2, LOW);
    digitalWrite(LED3, HIGH);
    delay(1000);
    digitalWrite(LED3, LOW);
 }
  else{
    digitalWrite(LED3, HIGH); 
    delay(1000);
    digitalWrite(LED3, LOW);
    digitalWrite(LED2, HIGH);
    delay(1000);
    digitalWrite(LED2, LOW);
    digitalWrite(LED1, HIGH);
    delay(1000);
    digitalWrite(LED1, LOW);
  }
}