void setup() {
  pinMode (7, OUTPUT);
  pinMode (6, OUTPUT);
  pinMode (5, OUTPUT);
  pinMode (4, OUTPUT);
  pinMode (3, OUTPUT);
  pinMode (2, OUTPUT);
  pinMode (1, OUTPUT);
  pinMode (0, OUTPUT);
}
void loop() {
    digitalWrite (7, HIGH);
    delay (1000);
    digitalWrite (7, LOW);
    delay (1000);
    digitalWrite (6, HIGH);
    delay (1000);
    digitalWrite (6, LOW);
    delay (1000);
    digitalWrite (5, HIGH);
    delay (1000);
    digitalWrite (5, LOW);
    delay (1000);
    digitalWrite (4, HIGH);
    delay (1000);
    digitalWrite (4, LOW);
    delay (1000);
     digitalWrite (3, HIGH);
    delay (1000);
    digitalWrite (3, LOW);
    delay (1000);
     digitalWrite (2, HIGH);
    delay (1000);
    digitalWrite (2, LOW);
    delay (1000);
     digitalWrite (1, HIGH);
    delay (1000);
    digitalWrite (1, LOW);
    delay (1000);
     digitalWrite (0, HIGH);
    delay (1000);
    digitalWrite (0, LOW);
    delay (1000);
}