// by avrige
int LED1 = 3;
int LED2 = 6;
int LED3 = 8;
int counter = 0;
 
void setup() {
  pinMode(LED1, OUTPUT);
  pinMode(LED2, OUTPUT);
  pinMode(LED3, OUTPUT);
}
 
void loop() {
            counter++;
            if(counter%2 == 0) {
      digitalWrite(LED1, HIGH);
            }
            if(counter%2 == 1) {
      digitalWrite(LED1, LOW);
            }
 
            if(counter%10 == 0) {
      digitalWrite(LED2, HIGH);
            }
            if(counter%10 == 5) {
      digitalWrite(LED2, LOW);
            }
 
            if(counter%50 == 0) {
      digitalWrite(LED3, HIGH);
            }
            if(counter%50 == 15) {
      digitalWrite(LED3, LOW);
            }
  delay(1000);
}