#define LED_PIN PA5       // Onboard LED pin
#define BUTTON_PIN PB0    // Push button pin

void setup() {
  pinMode(LED_PIN, OUTPUT);         // Set LED pin as output
  pinMode(BUTTON_PIN, INPUT_PULLUP); // Set button pin as input with pull-up resistor
}

void loop() {
  if (digitalRead(BUTTON_PIN) == LOW) { // Check if button is pressed
    for (int i = 0; i < 3; i++) {        // Blink LED three times
      digitalWrite(LED_PIN, HIGH);      // Turn LED on
      delay(200);                        // Wait for 200 ms
      digitalWrite(LED_PIN, LOW);       // Turn LED off
      delay(200);                        // Wait for 200 ms
    }
    while(digitalRead(BUTTON_PIN) == LOW); // Wait until button is released
  }
}