#define led 13
#define button 2
int reading ;
void setup() {
    pinMode(led,OUTPUT);
    pinMode(button,INPUT_PULLUP);
    digitalWrite(led,LOW);
}

void loop() {
    reading = digitalRead(button);
    delay(20);
    if(reading==0){
      digitalWrite(led, HIGH);
      delay(2000);
      digitalWrite(led,LOW);
      delay(2000);
    }
}