const int buttonPin = 4;
const int ledPin = 2;
int currentState;
int lastState = LOW;
int ledState = LOW;
void setup(){
  Serial.begin(9600);
  pinMode(ledPin,OUTPUT);
  pinMode(buttonPin,INPUT);
}
void loop(){
  currentState - digitalRead(buttonPin);

  if (lastState == LOW && currentState == HIGH){
    ledState = !ledState;
    digitalWrite(ledPin,ledState);
    Serial.println("stlacene");
  }
  else if (lastState == HIGH && currentState == LOW){
  Serial.println("uvolnene");
  }
 lastState = currentState;
 delay(50); 
  }