---

#define B1 6
#define B2 7
#define B3 8

#define GREEN 3
#define YELLOW 4
#define BLUE 5

void setup() {
  pinMode(B1, INPUT);
  pinMode(B2, INPUT);
  pinMode(B3, INPUT);

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

void loop() {
  int count = 0;

  if (digitalRead(B1) == HIGH) count++;
  if (digitalRead(B2) == HIGH) count++;
  if (digitalRead(B3) == HIGH) count++;

  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);
  }
}