arduino mega 2560 not working properly

happy it worked.
now i want to check that serial 1 pins rx & tx are working so i connect rx to tx for testing.
it display this
"104
104
104
104
104
104
104"

on serial monitor

void setup()
{
  Serial.begin(9600);
  Serial1.begin(9600);
  
}
void loop()
  {
  Serial1.write("hello"); 
  Serial.println(Serial1.read());
  delay(100);
  }