const int led1 = 2;
const int led2 = 3;
const int led3 = 4;
void setup() {
  Serial.begin(9600);
  Serial.println("Enter command");
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT);
}
void loop() {
  if (Serial.available() > 0) {
    String command = Serial.readString() ;
    command.trim();
    if (command == "L1_ON") {
      digitalWrite(led1, HIGH);
    }
    else if (command == "L1_OFF") {
      digitalWrite(led1, LOW);
    }
    else if (command == "L2_ON") {
      digitalWrite(led2, HIGH);
    }
    else if (command == "L2_OFF") {
      digitalWrite(led2, LOW);
    }
    else if (command == "L3_ON") {
      digitalWrite(led3, HIGH);
    }
    else if (command == "L3_OFF") {
      digitalWrite(led3, LOW);
    }
    else {
      Serial.println("Typing error");
    }
  }
}