int buttonPin=11;
int LedPin=12;

bool idk=0;
bool buttonState=0;
bool lastButtonState=0;
bool LedState=0;

unsigned long lastDebounceTime=0;
unsigned long BeforeTime=0;

int debounceDelay=50;
int Interval = 1000;
String PomocnaHodnota;

void setup() {
pinMode(LedPin, OUTPUT);
pinMode(buttonPin, INPUT);
Serial.begin(9600);
}

void loop() {
bool reading = digitalRead(buttonPin);
if (reading != lastButtonState) 
{
lastDebounceTime = millis();
}
if ((millis() - lastDebounceTime) > debounceDelay) 
{
if (reading != buttonState) 
{
buttonState = reading;
if (buttonState == HIGH) 
{
idk=!idk;
}
}
}
if(idk==1)
{
if(millis()-BeforeTime>=Interval)
{
BeforeTime =millis();
LedState=!LedState;
digitalWrite(LedPin,LedState);
}
}
else

digitalWrite(LedPin,0);
lastButtonState = reading;

if (Serial.available()>0) {
    PomocnaHodnota=Serial.readString();
    PomocnaHodnota.trim();
    int Time = PomocnaHodnota.toInt();
        if (Time>0 && Time<=10) {
          Time= Time*1000;
          Interval=Time;
          }
        else {
        Serial.println("Zadal si nespravnu hodnotu, skus to znova");
        Interval=0;
        digitalWrite(LedPin, LOW);
        }
  }
}