const int led1 = 9;  
const int led2 = 10;  

void setup(){
  pinMode(9, OUTPUT);
  pinMode(10,OUTPUT);
}
void loop(){
  for(int i=0; i<10; i++){
  digitalWrite(9, HIGH);
  delay(250);
  digitalWrite(10, HIGH);
  delay(250);
  digitalWrite(9, LOW);
  delay(500);
  digitalWrite(10,LOW);
  delay(500);
  }
for(int i=0; i<5; i++){
  for(int lightUp=0; lightUp<255; lightUp++){
    analogWrite(9,lightUp);
    analogWrite(10,255-lightUp);
    delay(10);
  }
  for(int lightUp=255; lightUp>0; lightUp--){
    analogWrite(9,lightUp);
    analogWrite(10,255-lightUp);
    delay(10);

  }
  for(int i=0; i<10; i++){
     for(int lightUp=0; lightUp<255; lightUp++){
    analogWrite(9,lightUp);
    analogWrite(10,255-lightUp);
    delay(10-i);
  }
    for(int lightUp=255; lightUp>0; lightUp--){
    analogWrite(9,lightUp);
    analogWrite(10,255-lightUp);
    delay(10-i);

  }
  }
}
}