int x = 0;
bool stav = HIGH;
void setup() 
{
  pinMode(A0, INPUT_PULLUP);
  Serial.begin(9600);
}

void loop()
{
  bool novyStav = digitalRead(A0);
  if(stav == HIGH && novyStav == LOW)
  {
    x = x + 1;
    Serial.println(x);
  }
  stav = novyStav;
  delay(130);
}