const int LED=12;
const int BUTTON=3;
void setup() {
  // put your setup code here, to run once:
pinMode(LED, OUTPUT);
pinMode(BUTTON, INPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  if(digitalRead(BUTTON)==1)
  {
    digitalWrite(LED, HIGH);
  }

  if(digitalRead(BUTTON)==0)
  {
    digitalWrite(LED, LOW);
  }
}