int pina=2;
int pinb=13;
int t=500;
int leda=6;
int ledb=4;
int i=0;
void setup() {
  // put your setup code here, to run once:
pinMode(pina, OUTPUT);
pinMode(pinb,OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
for (i=1;i<=leda; i=i+1){
  digitalWrite(pina, HIGH);
  delay(t);
  digitalWrite(pina, LOW);
  delay(t);
}
for (i=1;i<=ledb; i=i+1){
  digitalWrite(pinb, HIGH);
  delay(t);
  digitalWrite(pinb, LOW);
  delay(t);
}
}