int numero=1;
void setup() 
{
  Serial.begin(9600);
  pinMode(3, INPUT);
  pinMode(12, OUTPUT);
  pinMode(10, OUTPUT);
  pinMode(8, OUTPUT);
  pinMode(6, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(2, OUTPUT);
}
void loop() 
{
  if (digitalRead(3)==HIGH)
  {
    numero=numero+1;
    if (numero>6)
    {
      numero=1;
    }
    Serial.println(numero);
    apagarLed();
    prenderLed();
  }
}
void apagarLed()
{
  digitalWrite(12, LOW);
  digitalWrite(10, LOW);
  digitalWrite(8, LOW);
  digitalWrite(6, LOW);
  digitalWrite(4, LOW);
  digitalWrite(2, LOW);
}
void prenderLed()
{
  if (numero==1)
    {
      digitalWrite(12, HIGH);
    }
    if (numero==2)
    {
      digitalWrite(10, HIGH);
    }
    if (numero==3)
    {
      digitalWrite(8, HIGH);
    }
    if (numero==4)
    {
      digitalWrite(6,HIGH);
    }
    if (numero==5)
    {
      digitalWrite(4, HIGH);
    }
    if (numero==6)
    {
      digitalWrite(2, HIGH);
    }
}