int ledm = 8;
int ledk = 9;
int ledh = 10;
int ledb = 11;

void setup(){
  pinMode(ledm, OUTPUT);
  pinMode(ledk, OUTPUT);
  pinMode(ledh, OUTPUT);
  pinMode(ledb, OUTPUT);
}

void loop(){
  digitalWrite(ledm, HIGH);
  digitalWrite(ledk, HIGH);
  digitalWrite(ledh, HIGH);
  digitalWrite(ledb, HIGH);
  delay(500);
  digitalWrite(ledm, LOW);
  digitalWrite(ledk, LOW);
  digitalWrite(ledh, LOW);
  digitalWrite(ledb, LOW);
  delay(500);
}