const int l[]={25,26,27};
void setup() {
  // put your setup code here, to run once:
  for (int j=25; j<28 ;j++)
 {
  pinMode(j, OUTPUT);
 
}
}

void loop() {
  
 for (int i=0; i<3;i++){
  for  (char x=0; x<5; x++){
    digitalWrite(l[i], HIGH);
    delay(100);
    digitalWrite(l[i], LOW);
    delay(100);
  }
 }
}