void setup() {
  // put your setup code here, to run once:
  pinMode(13, OUTPUT);
  pinMode(3, INPUT);
  Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:

  if(digitalRead(3)==HIGH){
    digitalWrite(13,HIGH);
    Serial.println(digitalRead(3));
  }
  else{
    digitalWrite(13,LOW);
  }
}