Repetition by Using Original Input

/*
 * Jung Min Yean
 * March 19, 2019
 * First Program Ver1
 */
// define constants and variables
byte x = 3;
byte y = 0;
void setup()
{
  // declare your input and output
  Serial.begin(9600);
}
void loop()
{
  // put your main code here, to run repeatedly:
  y = x + 5;
  Serial.println(y);
}