void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
   for(int x=1;x<=5;x++){
    for(int i=1;i<=x;i++)
      Serial.print("*");
  Serial.println(" ");
  for(int j=5;j>=x;j--)
     Serial.print("*");
  }

}

void loop() {
Serial.println();
  delay(10); // this speeds up the simulation
}