//int led0 = 0; //onboard led
//int led1 = 1; //onboard led
//int led13 = 13; //onboard led
int led3 = 3;
int led4 = 4;
int led5 = 5;

void setup()
{
//pinMode(led0, OUTPUT);
//pinMode(led1, OUTPUT);
//pinMode(led13, OUTPUT);
pinMode(led3, OUTPUT);
//pinMode(led4, OUTPUT);
//pinMode(led5, OUTPUT);
}

void loop()
{
//digitalWrite(led0, 1);
//digitalWrite(led1, 1);
//digitalWrite(led13, 1);

digitalWrite(led3, 1);
//digitalWrite(led4, 1);
//digitalWrite(led5, 1);
delay(2000);

//digitalWrite(led0, 0);
//digitalWrite(led1, 0);
//digitalWrite(led13, 0);
digitalWrite(led3, 0);
//digitalWrite(led4, 0);
//digitalWrite(led5, 0);
delay(1000);
}