// 3 задание
void setup() {
  pinMode(13, OUTPUT);
  pinMode(2, INPUT_PULLUP);
  pinMode(A0, INPUT);
}

int lightThreshold = 250;
bool autoMode = true;

void loop() {
  if (digitalRead(2) == LOW) {
    autoMode = !autoMode;
    delay(300); 
    
 
    if (!autoMode) {
      digitalWrite(13, LOW);
    }
  }
  
  if (autoMode) {
    int lightValue = analogRead(A0);
    
    if (lightValue < lightThreshold) {
      digitalWrite(13, HIGH);
    } else {
      digitalWrite(13, LOW);
    }
  }
}