int led1=8;
int led2=9;
int led3=10;
int choice;
void setup(){
  pinMode(led1, OUTPUT);
  pinMode(led2,OUTPUT);
  pinMode(led3, OUTPUT);
  Serial.begin(9600);
  Serial.println("Enter a number(1-3):");
}
void loop(){
  if(Serial.available()>0) {
    choice=Serial.parseInt();
    switch(choice){
      case1:
      digitalWrite(led1, HIGH);
      digitalWrite(led2, LOW);
      digitalWrite(led3, LOW);
      Serial.println("Led is ON");
      break;

      case2:
      digitalWrite(led1, LOW);
      digitalWrite(led2, HIGH);
      digitalWrite(led3, LOW);
      Serial.println("Led is ON");
      break;

      case3:
      digitalWrite(led1, LOW);
      digitalWrite(led2, LOW);
      digitalWrite(led3, HIGH);
      Serial.println("Led is ON");
      break;

      default:
      digitalWrite(led1, LOW);
      digitalWrite(led2, LOW);
      digitalWrite(led3, LOW);
      Serial.println("Led is OFF");
      break;
    }
  }
}