int a=9;
int b=8; 
int c=7;
int d=6;
int e=5; 
int f=4;
int g=3;




void setup() {
  // put your setup code here, to run once:
  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:
// to display "0"

digitalWrite(a, LOW);
digitalWrite(b, LOW);
digitalWrite(c, LOW);
digitalWrite(d, LOW);
digitalWrite(e, LOW);
digitalWrite(f, LOW);
digitalWrite(g, HIGH);
  delay(500); // this speeds up the simulation

digitalWrite(a, HIGH);
digitalWrite(b, LOW);
digitalWrite(c, LOW);
digitalWrite(d, HIGH);
digitalWrite(e, HIGH);
digitalWrite(f, HIGH);
digitalWrite(g, HIGH);
  delay(500); // this speeds up the simulation
}