#include "Arduino.h"

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("**** Hello world ****");
}


void loop() {
  // put your main code here, to run repeatedly:
  int a;
  int b;
  int c;
  int d;
  int f = 10;

  a = f + 5;
  b = f - 5;
  c = f * 5;
  d = f / 5;

  Serial.printf("a => %d\r\n",a);
  Serial.printf("b => %d\r\n",b);
  Serial.printf("c => %d\r\n",c);
  Serial.printf("d => %d\r\n",d);


  while(true);

}