void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
pinMode(A0, INPUT_PULLUP);
}
int count = 0;
bool pkey = false;

void loop() {
  // put your main code here, to run repeatedly:
bool key = digitalRead(A0);
delay(10);



 if (key && !pkey){
 pkey = true;
 count++;
 }
  if(!key && pkey){
  pkey = false;
  }


   Serial.println(count);
   }