int value;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
pinMode(13, OUTPUT);
pinMode(4, INPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
if(1 == !digitalRead(4) ){
  value = 1;
}
  digitalWrite(13, value);
  Serial.print(F("value: "));
  Serial.println(value);
}