int a = 2;
int b = 3;
int c = 4;
int d = 5;
int e = 6;
int f = 7;
int g = 8;

void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
pinMode(a, OUTPUT);
pinMode(b, OUTPUT);
pinMode(c, OUTPUT);
pinMode(d, OUTPUT);
pinMode(e, OUTPUT);
pinMode(f, OUTPUT);
pinMode(g, OUTPUT);

}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(a,HIGH); //1
digitalWrite(b,LOW);
digitalWrite(c,LOW);
digitalWrite(d,HIGH);
digitalWrite(e,HIGH);
digitalWrite(f,HIGH);
digitalWrite(g,HIGH);
delay(2000);

digitalWrite(a,LOW);//2
digitalWrite(b,LOW);
digitalWrite(c,HIGH);
digitalWrite(d,LOW);
digitalWrite(e,LOW);
digitalWrite(f,HIGH);
digitalWrite(g,LOW);
delay(2000);

digitalWrite(a,HIGH);//3
digitalWrite(b,LOW);
digitalWrite(c,LOW);
digitalWrite(d,HIGH);
digitalWrite(e,HIGH);
digitalWrite(f,HIGH);
digitalWrite(g,HIGH);
delay(2000);
digitalWrite(a,HIGH);
digitalWrite(b,LOW);
digitalWrite(c,LOW);
digitalWrite(d,HIGH);
digitalWrite(e,HIGH);
digitalWrite(f,HIGH);
digitalWrite(g,HIGH);
delay(2000);
digitalWrite(a,HIGH);
digitalWrite(b,LOW);
digitalWrite(c,LOW);
digitalWrite(d,HIGH);
digitalWrite(e,HIGH);
digitalWrite(f,HIGH);
digitalWrite(g,HIGH);
delay(2000);
digitalWrite(a,HIGH);
digitalWrite(b,LOW);
digitalWrite(c,LOW);
digitalWrite(d,HIGH);
digitalWrite(e,HIGH);
digitalWrite(f,HIGH);
digitalWrite(g,HIGH);
delay(2000);
}