void setup() {
  // put your setup code here, to run once:
pinMode (12, OUTPUT);
pinMode (11, OUTPUT);
pinMode (10, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
int intervalo01;
intervalo01 = 250;

int intervalo02;
intervalo02 = 350;

int intervalo03;
intervalo03 = 450;

digitalWrite (12, HIGH);
digitalWrite (11, LOW);
delay(intervalo01);

digitalWrite (11, LOW);
digitalWrite (10, LOW);
delay (intervalo02);

digitalWrite (10, HIGH);
digitalWrite (12, LOW);
digitalWrite (11, HIGH);
delay (intervalo03);
}