int led12 = 12;
int led10  = 10;
void setup() {
  // put your setup code here, to run once:
pinMode(led12 , OUTPUT);
pinMode(led10 , OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(led12 , HIGH);
digitalWrite(led10, HIGH);
delay(100);
digitalWrite(led10 , LOW);
digitalWrite(led12 , LOW);
delay(100);
}