#define OFF 0
#define ON 1
#define LED_PIN 4
#define SWITCH_PIN 13
int toggle = OFF;


void setup() {
  // put your setup code here, to run once:
pinMode(SWITCH_PIN, INPUT_PULLUP);
pinMode(LED_PIN, OUTPUT);

}

void loop() {
if (digitalRead(SWITCH_PIN) == HIGH || toggle == ON){
  toggle = ON;
  while (digitalRead(SWITCH_PIN)== HIGH){
    led_flush();
  }
  led_flush();
} 
if (digitalRead(SWITCH_PIN)== HIGH && toggle== ON){
toggle = OFF ;
while (digitalRead(SWITCH_PIN) == HIGH){
  led_flush();
}
}
}

void led_flush(){
  digitalWrite(LED_PIN, HIGH);
  delay(300);
  digitalWrite(LED_PIN, LOW);
  delay(300);

}