#define BUTTON 25 
#define LED 5 

int button_state;
int led_state = LOW;

void setup() {
    pinMode(LED, OUTPUT);
    pinMode(BUTTON, INPUT_PULLUP);

}

void loop() {
  button_state = digitalRead(BUTTON);
  if(button_state==LOW) {
    led_state = !led_state;
    digitalWrite(LED,led_state);
    delay(1000);

  }
}