int KMUTNB = 1;
int LED3 = 2;
void setup() {
  Serial1.begin(115200);
  Serial1.println("Hello, Cute Students");
  pinMode(LED3, OUTPUT);
}

void loop() {
  digitalWrite(LED3, HIGH);
  delay(1000); 
  digitalWrite(LED3, LOW);
  delay(1000); 
  Serial1.print("my KMUTNB =");
  Serial1.println(KMUTNB);
  KMUTNB++;
}