#define LED_PIN1 3
#define LED_PIN2 4
#define LED_PIN3 5
#define BTN_PIN1 6
#define BTN_PIN2 7
#define BTN_PIN3 8
void setup() {
pinMode(LED_PIN1, OUTPUT);
pinMode(LED_PIN2, OUTPUT);
pinMode(LED_PIN3, OUTPUT);
pinMode(BTN_PIN1, INPUT);
pinMode(BTN_PIN2, INPUT);
pinMode(BTN_PIN3, INPUT);
}

void loop() {
int btn_state1 = digitalRead(BTN_PIN1);
int btn_state2 = digitalRead(BTN_PIN2);
int btn_state3 = digitalRead(BTN_PIN3);
int button_c = btn_state1 + btn_state2 + btn_state3;
if (button_c == 1)
{
  digitalWrite(LED_PIN1, HIGH);
  digitalWrite(LED_PIN2, LOW);
  digitalWrite(LED_PIN3, LOW);
}
else if (button_c == 2)
{
  digitalWrite(LED_PIN1, LOW);
  digitalWrite(LED_PIN2, HIGH);
  digitalWrite(LED_PIN3, LOW);
}
else if (button_c == 3)
{
  digitalWrite(LED_PIN1, LOW);
  digitalWrite(LED_PIN2, LOW);
  digitalWrite(LED_PIN3, HIGH);
}
else{
  digitalWrite(LED_PIN1, LOW);
  digitalWrite(LED_PIN2, LOW);
  digitalWrite(LED_PIN3,LOW);
}
}