void setup()
{
  pinMode(7, OUTPUT);
  pinMode(6, OUTPUT);
  pinMode(5, OUTPUT);
}

void loop()
{
  digitalWrite(7, HIGH);
  delay(50); // Wait for 1000 millisecond(s)
  digitalWrite(7, LOW);
  delay(100); // Wait for 1000 millisecond(s)
  digitalWrite(6, HIGH);
  delay(50); // Wait for 1000 millisecond(s)
  digitalWrite(6, LOW);
  delay(100); // Wait for 1000 millisecond(s)
  digitalWrite(5, HIGH);
  delay(50); // Wait for 1000 millisecond(s)
  digitalWrite(5, LOW);
  delay(100); // Wait for 1000 millisecond(s)
}