void setup() 
{
for (int i=11;i>=3;i=i-2)
pinMode(i, OUTPUT);
}

void loop() {

for (int i=11;i>=3;i=i-2) 
{
 digitalWrite(i, HIGH);
 delay(200);
 digitalWrite(i, LOW);
}

delay(1000);

for (int i=3;i<=11;i=i+2) 
{
 digitalWrite(i, HIGH);
 delay(200);
 digitalWrite(i, LOW);
}

delay(1000);

for (int i=11;i>=3;i=i-2) 
{
 digitalWrite(i, HIGH);
delay(200);
}

delay(1000);

for (int i=11;i>=3;i=i-2) 
{
 digitalWrite(i, LOW);
}

delay(1000);

for (int i=3;i<=11;i=i+2) 
{
 digitalWrite(i, HIGH);
 delay(200);
 
}

delay(1000);

for (int i=3;i<=11;i=i+2) 
{
 digitalWrite(i, LOW);
}

delay(1000);



}