int shreya = 12,kitty=11,cat=10;
void setup() {
  // put your setup code here, to run once:
pinMode(shreya, OUTPUT);
pinMode(kitty,OUTPUT);
pinMode(cat,OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
 while(1){
  digitalWrite(shreya,HIGH);
delay(1000);
  digitalWrite(shreya,LOW);
delay(1000);
digitalWrite(kitty,HIGH);
delay(1000);
  digitalWrite(kitty,LOW);
delay(1000);
digitalWrite(cat,HIGH);
delay(1000);
  digitalWrite(cat,LOW);
delay(1000);
 }
}