const int LED = 3;
const int BUTTON = 10;
int pressed = 0;
int state = 0;

void setup() {
  pinMode(LED, OUTPUT);
  pinMode(BUTTON, INPUT);
  digitalWrite(LED, LOW);
  Serial.begin(9600);
}

void loop() {
  pressed = digitalRead(BUTTON);

  if (pressed == 1 && state == 0)
  {
    digitalWrite(LED, HIGH);
    state = 1;
  }
  else if (pressed == 1 && state == 1)
  {
    digitalWrite(LED, LOW);
    state = 0;
  }
  Serial.print(state);
}