const int aled = 4; // RED
const int bled = 2; // GREEN
const int cled = A3; // BLUE
const int dled = A5; // YELLOW

// note: set up is A B
//                 C D

void setup() {
  // put your setup code here, to run once:

}

void loop() {
  // put your main code here, to run repeatedly:

}