int a =12;
int b =27;
int c =25;
int x =4;
int y =5;
int z =19;
void setup()
{
  pinMode(a, OUTPUT);
  pinMode(b, OUTPUT);
  pinMode(c, OUTPUT);
  pinMode(x, OUTPUT);
  pinMode(y, OUTPUT);
  pinMode(z, OUTPUT);
}
void loop()
{
  digitalWrite(a, HIGH);
  digitalWrite(y, HIGH);
  delay(2000);
  digitalWrite(a, LOW);
  digitalWrite(y, LOW);
  delay(2000);
  digitalWrite(b, HIGH);
  digitalWrite(x, HIGH);
  delay(2000);
  digitalWrite(b, LOW);
  digitalWrite(x, LOW);
  delay(2000);
  digitalWrite(c, HIGH);
  digitalWrite(z, HIGH);
  delay(2000);
  digitalWrite(c, LOW);
  digitalWrite(z, LOW);
  delay(2000);
  
}