int buttonState = 0; the board
void setup() {
  // initialize digital pin LED_BUILTIN as an output.
  pinMode(2, OUTPUT);
  pinMode(3, INPUT);
}

// the loop function runs over and over again forever
void loop() {
  buttonState = digitalRead(3);
  if(buttonState == HIGH){
    digitalWrite(2, HIGH);   // turn the LED on (HIGH is the voltage level)
    delay(1000);                       // wait for a second
    digitalWrite(2, LOW);    // turn the LED off by making the voltage LOW
    delay(1000);
  }// wait for a second
}