57. Arduino UART Programming

What will be printed on the Serial Monitor when the following code runs if no data is sent to the Arduino?

void setup() {
  Serial.begin(9600);
}
void loop() {
  if (Serial.available() > 0) {
    int incomingByte = Serial.read();
    Serial.print("Received: ");
    Serial.println(incomingByte);
  }
}