int pinG = 13;
int pinY = 12;
int pinR = 11;

int pinB = 2;

int hodnota = HIGH;
const OFF = HIGH;
const ON = LOW;

void setup() {
 pinMode (pinG, OUTPUT);
 pinMode (pinY, OUTPUT);
 pinMode (pinR, OUTPUT);

 pinMode (pinB, INPUT);

 Serial.begin(9600);

}

void loop(){
hodnota = digitalRead(pinB);
Serial.println(hodnota);
 if (hodnota == ON){
  digitalWrite(pinG, HIGH);
  delay(500);
 }

}