int a= 27;
int b=26;
int c  =14;
int d=21;
int e=19;
 int f=18;
void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(a, OUTPUT);
  pinMode(b, OUTPUT);
  pinMode(c, OUTPUT);
  pinMode(d, OUTPUT);
  pinMode(e, OUTPUT);
  pinMode(f, OUTPUT);
}

void loop() {
  digitalWrite(a,HIGH);
digitalWrite(f,HIGH);
 digitalWrite(b,LOW);
  digitalWrite(e,LOW);
   digitalWrite(c,LOW);
  digitalWrite(d,LOW);

  delay(1000);
   // this speeds up the simulation
    digitalWrite(a,LOW);
    digitalWrite(f,LOW);
    digitalWrite(b,HIGH);
    digitalWrite(e,HIGH);
     digitalWrite(c,LOW);
  digitalWrite(d,LOW);
    delay(1000);
  digitalWrite(a,LOW);
  digitalWrite(f,LOW);
  digitalWrite(b,LOW);
  digitalWrite(e,LOW);
  digitalWrite(c,HIGH);
  digitalWrite(d,HIGH);
  delay(1000);
}