#define led1 13
#define led2 12
#define led3 11
#define led4 10

byte state = LOW;
void setup() {
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT);
  pinMode(led4, OUTPUT);
  Serial.begin(9600);
  
}

void loop() {
  noInterrupts();
  Serial.print("disable interrupt : ");
  for(int i=1;i<=20;i++){
    Serial.print("-");Serial.print(i);delay(250);
    state = !state;
    digitalWrite(led1,state);
  }
  Serial.println("");
  interrupts();
  Serial.print("Enable interrupts : ");
  for(int i=1;i<=20;i++){
    Serial.print(".");Serial.print(i);delay(250);
    state = !state;
    digitalWrite(led2,state);
  }
  Serial.println("");

}