#define LED1 2
#define LED2 4
#define LED3 5
#define LED4 13

void setup() {
  pinMode(LED1, OUTPUT);
  pinMode(LED2, OUTPUT);
  pinMode(LED3, OUTPUT);
  pinMode(LED4, OUTPUT);
  Serial.begin(9600);
  Serial.println("Input a number:");
}

void loop() {
if(Serial.available()>0){
  int a = Serial.parseInt();
  Serial.read();
  Serial.println(a);
if(a > 10){
  digitalWrite(LED1, LOW);
  digitalWrite(LED3, LOW);
  delay(500);
  digitalWrite(LED2, HIGH);
  digitalWrite(LED4, HIGH);
  delay(500);
  digitalWrite(LED2, LOW);
  digitalWrite(LED4, LOW);
 } if(a <= 10){
  digitalWrite(LED1, LOW);
  digitalWrite(LED2, LOW);
  digitalWrite(LED3, LOW);
  digitalWrite(LED4, LOW);
 }
}
}