#define LED1 PA9
#define LED2 PA10
#define LED3 PA11
#define LED4 PA12
int leds[] = {LED1, LED2, LED3, LED4};

void setup() {

  for(int i = 0; i < 5; i++) { 
    pinMode(leds[i], OUTPUT);
    digitalWrite(leds[i], LOW); 
  }
}

void loop() {

  for(int i = 0; i < 5; i++) {
    digitalWrite(leds[i], HIGH);  
    delay(200);                   
    digitalWrite(leds[i], LOW); 
  }
}