const int LedR = 3;
const int LedY = 2;
const int LedG = 1;
const int pinButtonR = 5;
const int pinButtonY = 6;
const int pinButtonG = 7;

bool isRPressed = false;
bool isYPressed = false;
bool isGPressed = false;

void setup() {
  pinMode(LedG, OUTPUT);
  pinMode(LedY, OUTPUT);
  pinMode(LedR, OUTPUT);
  pinMode(pinButtonR, INPUT_PULLUP);
  pinMode(pinButtonY, INPUT_PULLUP);
  pinMode(pinButtonG, INPUT_PULLUP); 
}

void loop() { 
  if (digitalRead(pinButtonR) == LOW ) {
    isRPressed = !isRPressed; 
    if (isRPressed) {
      digitalWrite(LedG, LOW);
      digitalWrite(LedY, LOW);
      digitalWrite(LedR, HIGH);
      isYPressed = false; 
      isGPressed = false;
    } else {
      digitalWrite(LedR, LOW);
    }
    delay(100); 
  }
  
  if (digitalRead(pinButtonY) == LOW) {
    isYPressed = !isYPressed; 
    if (isYPressed) {
      digitalWrite(LedG, LOW);
      digitalWrite(LedR, LOW);
      digitalWrite(LedY, HIGH);
      isRPressed = false; 
      isGPressed = false;
    } else {
      digitalWrite(LedY, LOW);
    }
    delay(100);
  }
  
  if (digitalRead(pinButtonG) == LOW) {
    isGPressed = !isGPressed;
    if (isGPressed) {
      digitalWrite(LedY, LOW);
      digitalWrite(LedR, LOW);
      digitalWrite(LedG, HIGH);
      isRPressed = false;
      isYPressed = false;
    } else {
      digitalWrite(LedG, LOW);
    }
    delay(100);
  }
}