#define led1 A0
#define led2 A1
#define led3 A2
#define led4 A3
#define led5 A4
#define led6 A5
void setup() {
  // put your setup code here, to run once:
pinMode(led1,OUTPUT);
pinMode(led2,OUTPUT);
pinMode(led3,OUTPUT);
pinMode(led4,OUTPUT);
pinMode(led5,OUTPUT);
pinMode(led6,OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(led1,HIGH);
delay(1000);
digitalWrite(led1,LOW);
delay(500);
digitalWrite(led2,HIGH);
delay(1000);
digitalWrite(led2,LOW);
delay(500);
digitalWrite(led3,HIGH);
delay(1000);
digitalWrite(led3,LOW);
delay(500);
digitalWrite(led4,HIGH);
delay(1000);
digitalWrite(led4,LOW);
delay(500);
digitalWrite(led5,HIGH);
delay(1000);
digitalWrite(led5,LOW);
delay(500);
digitalWrite(led6,HIGH);
delay(1000);
digitalWrite(led6,LOW);
delay(500);
}