int val=3;
int stop=7;
int dim=1;
int zmena=0;
void setup() {
  pinMode(A0, INPUT);
  attachInterrupt(digitalPinToInterrupt(18),reset,HIGH);
}

void loop() {
  int a=analogRead(A0);
  while (zmena=1) {
    dim--;
    analogWrite(val, dim);
    delay(a);
    if (dim=1) {
      val++;
      zmena=0;
    }
  }
  while (zmena=0){
    dim++;
    analogWrite(val, dim);
    delay(a);
    if (dim=1023,val<stop) {
      zmena=1;
    }
    if (val >= stop) {
    val=3;
    stop --;
    }
  }
}

void reset() {
  val=3;
  stop=7;
  zmena=0;
  digitalWrite(13, LOW);
  digitalWrite(12, LOW);
  digitalWrite(11,LOW);
  digitalWrite(10,LOW);
  digitalWrite(9,LOW);
}