void setup() {
 pinMode(4, INPUT_PULLUP);
 pinMode(2, OUTPUT);
 pinMode(3, OUTPUT);
}

void loop() {
 int x= analogRead(A0);

 if (digitalRead(4)==LOW)
  {
    digitalWrite(3,HIGH);
    delay(x);
    digitalWrite(2,HIGH);
    delay(x);
    digitalWrite(3,LOW);
    delay(x);
    digitalWrite(2,LOW);
    delay(x);
  }
}