int count = 0;
int pause = 200;
void setup() {
  
  // put your setup code here, to run once:
  pinMode(3, INPUT_PULLUP);
  pinMode(5, OUTPUT);
  pinMode(6, OUTPUT);
  pinMode(7, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  if (digitalRead(3) == LOW) {

  }
  if (count == 1) {
    digitalWrite(5, HIGH);
  }
  else if (count == 2) {
    digitalWrite(6, HIGH);
  }
  else if (count == 3) {
    digitalWrite(7, HIGH);
  }
  else if (count >= 4) {
    digitalWrite(5, LOW);
    digitalWrite(6, LOW);
    digitalWrite(7, LOW);
    count = 0;
  }
  delay(200);
}