void setup() {
  Serial.begin(9600);
  pinMode(2, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);
  pinMode(6, OUTPUT);
  pinMode(7, OUTPUT);
}

void loop() {
  int randomValue = random(1, 6+1);
  if( randomValue == 1){
    digitalWrite(2, HIGH);
    digitalWrite(5, LOW);
    digitalWrite(4, LOW);
    digitalWrite(3, LOW);
    digitalWrite(6, LOW);
    digitalWrite(7, LOW);
  }
   if( randomValue == 2){
    digitalWrite(3, HIGH);
    digitalWrite(5, LOW);
    digitalWrite(4, LOW);
    digitalWrite(2, LOW);
    digitalWrite(6, LOW);
    digitalWrite(7, LOW);
  }
 if( randomValue == 3){
    digitalWrite(4, HIGH);
    digitalWrite(5, LOW);
    digitalWrite(2, LOW);
    digitalWrite(3, LOW);
    digitalWrite(6, LOW);
    digitalWrite(7, LOW);
  }
   if( randomValue == 4){
    digitalWrite(5, HIGH);
    digitalWrite(2, LOW);
    digitalWrite(4, LOW);
    digitalWrite(3, LOW);
    digitalWrite(6, LOW);
    digitalWrite(7, LOW);
  }
   if( randomValue == 5){
    digitalWrite(6, HIGH);
    digitalWrite(5, LOW);
    digitalWrite(4, LOW);
    digitalWrite(3, LOW);
    digitalWrite(2, LOW);
    digitalWrite(7, LOW);
  }
   if( randomValue == 6){
    digitalWrite(7, HIGH);
    digitalWrite(5, LOW);
    digitalWrite(4, LOW);
    digitalWrite(3, LOW);
    digitalWrite(6, LOW);
    digitalWrite(2, LOW);
  }
  delay(100);
}