// Muhammadi
#define button 2
#define led 3
void setup() {
  Serial.begin(9600);
  pinMode(button, INPUT_PULLUP);  
}
bool flag = 0;
int act = 0;
int brightness = 255;
void loop() {
  if(digitalRead(button) == 0){
    if(flag == 1){
      int time = millis();
      act = time;
      while(digitalRead(button) == 0){
        if(millis() - time > 400){
          Serial.print(brightness);
          time = millis();
          if(brightness > 40){
            brightness -= 40;
          }
          analogWrite(led, brightness);
        }
      }
      if(millis() - act < 400){
        analogWrite(led, 0);
        flag = 0;
      }
    }
    else{
      while(digitalRead(button) == 0){}
      brightness = 255;
      flag = 1;
      analogWrite(led, 255);
    }
  }
}
!highlight!