---

#define BTN1 3
#define BTN2 5
#define BTN3 6

#define GREEN 8
#define YELLOW 9
#define BLUE 10

void setup() {
  pinMode(BTN1, INPUT);
  pinMode(BTN2, INPUT);
  pinMode(BTN3, INPUT);

  pinMode(GREEN, OUTPUT);
  pinMode(YELLOW, OUTPUT);
  pinMode(BLUE, OUTPUT);
}

void loop() {

  int b1 = digitalRead(BTN1);
  int b2 = digitalRead(BTN2);
  int b3 = digitalRead(BTN3);

  int count = b1 + b2 + b3;

  if (count == 1) {
    digitalWrite(GREEN, HIGH);
    digitalWrite(YELLOW, LOW);
    digitalWrite(BLUE, LOW);
  }

  if (count == 2) {
    digitalWrite(GREEN, LOW);
    digitalWrite(YELLOW, HIGH);
    digitalWrite(BLUE, LOW);
  }

  if (count == 3) {
    digitalWrite(GREEN, LOW);
    digitalWrite(YELLOW, LOW);
    digitalWrite(BLUE, HIGH);
  }

  if (count == 0) {
    digitalWrite(GREEN, LOW);
    digitalWrite(YELLOW, LOW);
    digitalWrite(BLUE, LOW);
  }
}