int per=180;
int i ;
int j;
void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
pinMode(3, OUTPUT);
pinMode(5, OUTPUT);
pinMode(7, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  step_1();
  step_2();
  step_3();
  step_2();
  }
  void step_1(){
    for (j=3;j>=1;j=j-1){
  for (i=7;i>=1;i=i-2){
    digitalWrite(i, HIGH);
    delay(per);
    digitalWrite(i, LOW);}
  }}
void step_2(){
  for (j=3;j>=1;j=j-1){
  digitalWrite(3, HIGH);
  digitalWrite(5, HIGH);
  digitalWrite(7, HIGH);
  delay(per);
  digitalWrite(3, LOW);
  digitalWrite(5, LOW);
  digitalWrite(7, LOW);
  delay(per);}
}
void step_3(){
  for (j=3;j>=1;j=j-1){
  for (i=3;i<=9;i=i+2){
digitalWrite(i, HIGH);
delay(per);
digitalWrite(i, LOW);
  }
}}