void setup() {
  pinMode(0, OUTPUT);
  pinMode(1, OUTPUT);
  pinMode(2, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);
  pinMode(6, OUTPUT);
  pinMode(7, OUTPUT);
  pinMode(8, OUTPUT);
  pinMode(9, OUTPUT);
  pinMode(10, OUTPUT);
  pinMode(11, OUTPUT);
  pinMode(12, OUTPUT);
  pinMode(13, OUTPUT);
  pinMode(14, OUTPUT);
  pinMode(15, OUTPUT);
  pinMode(16, OUTPUT);
  pinMode(17, OUTPUT);
  pinMode(18, OUTPUT);
  pinMode(19, OUTPUT);
}

void setLEDs(long leds) {
  if (leds & 0b00000000000000000001) digitalWrite(0, HIGH); else digitalWrite(0, LOW);
  if (leds & 0b00000000000000000010) digitalWrite(1, HIGH); else digitalWrite(1, LOW);
  if (leds & 0b00000000000000000100) digitalWrite(2, HIGH); else digitalWrite(2, LOW);
  if (leds & 0b00000000000000001000) digitalWrite(3, HIGH); else digitalWrite(3, LOW);
  if (leds & 0b00000000000000010000) digitalWrite(4, HIGH); else digitalWrite(4, LOW);
  if (leds & 0b00000000000000100000) digitalWrite(5, HIGH); else digitalWrite(5, LOW);
  if (leds & 0b00000000000001000000) digitalWrite(6, HIGH); else digitalWrite(6, LOW);
  if (leds & 0b00000000000010000000) digitalWrite(7, HIGH); else digitalWrite(7, LOW);
  if (leds & 0b00000000000100000000) digitalWrite(8, HIGH); else digitalWrite(8, LOW);
  if (leds & 0b00000000001000000000) digitalWrite(9, HIGH); else digitalWrite(9, LOW);
  if (leds & 0b00000000010000000000) digitalWrite(10, HIGH); else digitalWrite(10, LOW);
  if (leds & 0b00000000100000000000) digitalWrite(11, HIGH); else digitalWrite(11, LOW);
  if (leds & 0b00000001000000000000) digitalWrite(12, HIGH); else digitalWrite(12, LOW);
  if (leds & 0b00000010000000000000) digitalWrite(13, HIGH); else digitalWrite(13, LOW);
  if (leds & 0b00000100000000000000) digitalWrite(14, HIGH); else digitalWrite(14, LOW);
  if (leds & 0b00001000000000000000) digitalWrite(15, HIGH); else digitalWrite(15, LOW);
  if (leds & 0b00010000000000000000) digitalWrite(16, HIGH); else digitalWrite(16, LOW);
  if (leds & 0b00100000000000000000) digitalWrite(17, HIGH); else digitalWrite(17, LOW);
  if (leds & 0b01000000000000000000) digitalWrite(18, HIGH); else digitalWrite(18, LOW);
  if (leds & 0b10000000000000000000) digitalWrite(19, HIGH); else digitalWrite(19, LOW);
}

void loop() {
  setLEDs(0b00000000000000000001);  delay(200);
  setLEDs(0b00000000000000000010);  delay(200);
  setLEDs(0b00000000000000000100);  delay(200);
  setLEDs(0b00000000000000001000);  delay(200);
  setLEDs(0b00000000000000010000);  delay(200);
  setLEDs(0b00000000000000100000);  delay(200);
  setLEDs(0b00000000000001000000);  delay(200);
  setLEDs(0b00000000000010000000);  delay(200);
  setLEDs(0b00000000000100000000);  delay(200);
  setLEDs(0b00000000001000000000);  delay(200);
  setLEDs(0b00000000010000000000);  delay(200);
  setLEDs(0b00000000100000000000);  delay(200);
  setLEDs(0b00000001000000000000);  delay(200);
  setLEDs(0b00000010000000000000);  delay(200);
  setLEDs(0b00000100000000000000);  delay(200);
  setLEDs(0b00001000000000000000);  delay(200);
  setLEDs(0b00010000000000000000);  delay(200);
  setLEDs(0b00100000000000000000);  delay(200);
  setLEDs(0b01000000000000000000);  delay(200);
  setLEDs(0b10000000000000000000);  delay(200);
}