const int Red=13, Green=12;
void setup() 
{

    pinMode(12,OUTPUT);
    pinMode(Red,OUTPUT);

}

void loop() 
{
  
  for(int i=1; i<11; i++)
  {
    if(i%2==0)
    {
      digitalWrite(12, HIGH);
      digitalWrite(13, LOW);
      delay(1000);
    }
    else
    {
      digitalWrite(Red, HIGH);
      digitalWrite(12, LOW);
      delay(1000);
    }
  }

}