void setup() {
  // put your setup code here, to run once:
  pinMode(4, INPUT);
  pinMode(5, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  int i = digitalRead(4);
  if (i == 1)
  {
    digitalWrite(5, HIGH);
    delay(20);
  }
  else
  {
    digitalWrite(5, LOW);
    delay(20);
  }
}