int led1=12;
int led2=11;
int led3=10;
int led4=9;
int delayamt=500;
void setup() {
  // put your setup code here, to run once:
pinMode(led1,OUTPUT);
pinMode(led2,OUTPUT);
pinMode(led3,OUTPUT);
pinMode(led4,OUTPUT);
}

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