#define btn1 2   
#define btn2 4
#define btn3 5
#define LED1 11  
#define LED2 12 
#define LED3 13
#define restart 7 

bool lock = false;

void setup() {
pinMode(btn1, INPUT);
pinMode(btn2, INPUT);
pinMode(btn3, INPUT);
pinMode(LED1, OUTPUT);
pinMode(LED2, OUTPUT);
pinMode(LED3, OUTPUT);
pinMode(restart, INPUT);
}
void loop() {
  if(lock == false){
    if(digitalRead (btn1) == HIGH){
      digitalWrite(LED1, HIGH);
      lock = true;
    }
    else if(digitalRead (btn2) == HIGH){
      digitalWrite(LED2, HIGH);
      lock = true;
    }
    else if(digitalRead (btn3) == HIGH){
      digitalWrite(LED3, HIGH);
      lock = true;
    }
  }
  else{
    if(digitalRead (restart) == HIGH){
      lock = false;
      digitalWrite(LED1, LOW);
      digitalWrite(LED2, LOW);
      digitalWrite(LED3, LOW);
      delay(200);
    }
  }
}