int btn1;
int btn1lock;
int btn2;
int btn2lock;
int counter;

void setup(){
  pinMode(2, INPUT);
  pinMode(3, INPUT);
  btn1lock=1;
  btn2lock=1;
  Serial.begin(9600);
}

void loop() {
 btn1 = digitalRead(2);
 btn2 = digitalRead(3);
 if (btn1 == 1 && btn1lock ==1) {
counter++;
btn1lock =0;
Serial.println(counter);

 
 }
 if(btn1 == 0){
   btn1lock = 1;
  
 }
 delay(20);

 if (btn2 == 1 && btn2lock ==1) {
counter--;
btn2lock =0;
Serial.println(counter);

 
 }
 if(btn2 == 0){
   btn2lock = 1;
  
 }
 delay(20);

}